diff --git a/src/cpp/ripple/Ledger.cpp b/src/cpp/ripple/Ledger.cpp
index 3db595c5aa..803f240044 100644
--- a/src/cpp/ripple/Ledger.cpp
+++ b/src/cpp/ripple/Ledger.cpp
@@ -538,7 +538,24 @@ Ledger::pointer Ledger::loadByHash(const uint256& ledgerHash)
 	std::string sql="SELECT * from Ledgers WHERE LedgerHash='";
 	sql.append(ledgerHash.GetHex());
 	sql.append("';");
-	return getSQL(sql);
+	Ledger::pointer ret = getSQL(sql);
+	if (ret)
+		return ret;
+	HashedObject::pointer node = theApp->getHashedObjectStore().retrieve(ledgerHash);
+	if (!node)
+		return Ledger::pointer();
+	try
+	{
+		Ledger::pointer ledger = boost::make_shared<Ledger>(strCopy(node->getData()), true);
+		if (ledger->getHash() == ledgerHash)
+			return ledger;
+	}
+	catch (...)
+	{
+		cLog(lsDEBUG) << "Exception trying to load ledger by hash: " << ledgerHash;
+		return Ledger::pointer();
+	}
+	return Ledger::pointer();
 }
 
 Ledger::pointer Ledger::getLastFullLedger()
diff --git a/src/cpp/ripple/LedgerAcquire.cpp b/src/cpp/ripple/LedgerAcquire.cpp
index 55c539be1b..6312d61c4c 100644
--- a/src/cpp/ripple/LedgerAcquire.cpp
+++ b/src/cpp/ripple/LedgerAcquire.cpp
@@ -175,18 +175,21 @@ void LedgerAcquire::done()
 #endif
 	std::vector< boost::function<void (LedgerAcquire::pointer)> > triggers;
 
-	setComplete();
+	assert(isComplete() || isFailed());
+
 	mLock.lock();
 	triggers = mOnComplete;
 	mOnComplete.clear();
 	mLock.unlock();
 
-	if (mLedger)
+	if (isComplete() && mLedger)
 	{
 		if (mAccept)
 			mLedger->setAccepted();
 		theApp->getLedgerMaster().storeLedger(mLedger);
 	}
+	else if (isFailed())
+		theApp->getMasterLedgerAcquire().logFailure(mHash);
 
 	for (unsigned int i = 0; i < triggers.size(); ++i)
 		triggers[i](shared_from_this());
@@ -528,6 +531,21 @@ LedgerAcquire::pointer LedgerAcquireMaster::find(const uint256& hash)
 	return LedgerAcquire::pointer();
 }
 
+std::vector<uint256> LedgerAcquire::getNeededHashes()
+{
+	std::vector<uint256> ret;
+	if (!mHaveBase)
+	{
+		ret.push_back(mHash);
+		return ret;
+	}
+	if (!mHaveState)
+		mLedger->peekAccountStateMap()->getNeededHashes(ret, 16);
+	if (!mHaveTransactions)
+		mLedger->peekTransactionMap()->getNeededHashes(ret, 16);
+	return ret;
+}
+
 bool LedgerAcquireMaster::hasLedger(const uint256& hash)
 {
 	assert(hash.isNonZero());
@@ -621,4 +639,36 @@ SMAddNode LedgerAcquireMaster::gotLedgerData(ripple::TMLedgerData& packet, Peer:
 	return SMAddNode::invalid();
 }
 
+void LedgerAcquireMaster::logFailure(const uint256& hash)
+{
+	time_t now = time(NULL);
+	boost::mutex::scoped_lock sl(mLock);
+
+	std::map<uint256, time_t>::iterator it = mRecentFailures.begin();
+	while (it != mRecentFailures.end())
+	{
+		if (it->first == hash)
+		{
+			it->second = now;
+			return;
+		}
+		if (it->second > now)
+		{ // time jump or discontinuity
+			it->second = now;
+			++it;
+		}
+		else if ((it->second + 180) < now)
+			mRecentFailures.erase(it++);
+		else
+			++it;
+	}
+	mRecentFailures[hash] = now;
+}
+
+bool LedgerAcquireMaster::isFailure(const uint256& hash)
+{
+	boost::mutex::scoped_lock sl(mLock);
+	return mRecentFailures.find(hash) != mRecentFailures.end();
+}
+
 // vim:ts=4
diff --git a/src/cpp/ripple/LedgerAcquire.h b/src/cpp/ripple/LedgerAcquire.h
index 68753afab6..a4b54a3ae4 100644
--- a/src/cpp/ripple/LedgerAcquire.h
+++ b/src/cpp/ripple/LedgerAcquire.h
@@ -108,6 +108,8 @@ public:
 	void trigger(Peer::ref, bool timer);
 	bool tryLocal();
 	void addPeers();
+
+	std::vector<uint256> getNeededHashes();
 };
 
 class LedgerAcquireMaster
@@ -115,6 +117,7 @@ class LedgerAcquireMaster
 protected:
 	boost::mutex mLock;
 	std::map<uint256, LedgerAcquire::pointer> mLedgers;
+	std::map<uint256, time_t> mRecentFailures;
 
 public:
 	LedgerAcquireMaster() { ; }
@@ -124,6 +127,9 @@ public:
 	bool hasLedger(const uint256& ledgerHash);
 	void dropLedger(const uint256& ledgerHash);
 	SMAddNode gotLedgerData(ripple::TMLedgerData& packet, Peer::ref);
+
+	void logFailure(const uint256&);
+	bool isFailure(const uint256&);
 };
 
 #endif
diff --git a/src/cpp/ripple/LedgerMaster.cpp b/src/cpp/ripple/LedgerMaster.cpp
index db7faa57a3..c8eafcb4c7 100644
--- a/src/cpp/ripple/LedgerMaster.cpp
+++ b/src/cpp/ripple/LedgerMaster.cpp
@@ -170,6 +170,11 @@ void LedgerMaster::acquireMissingLedger(const uint256& ledgerHash, uint32 ledger
 		mMissingLedger.reset();
 		return;
 	}
+	else if (mMissingLedger->isDone())
+	{
+		mMissingLedger.reset();
+		return;
+	}
 	mMissingSeq = ledgerSeq;
 	if (mMissingLedger->setAccept())
 		mMissingLedger->addOnComplete(boost::bind(&LedgerMaster::missingAcquireComplete, this, _1));
@@ -290,7 +295,11 @@ void LedgerMaster::setFullLedger(Ledger::ref ledger)
 	}
 
 	if (mMissingLedger && mMissingLedger->isDone())
+	{
+		if (mMissingLedger->isFailed())
+			theApp->getMasterLedgerAcquire().dropLedger(mMissingLedger->getHash());
 		mMissingLedger.reset();
+	}
 
 	if (mMissingLedger || !theConfig.LEDGER_HISTORY)
 	{
@@ -397,7 +406,7 @@ void LedgerMaster::checkPublish(const uint256& hash, uint32 seq)
 		}
 	}
 
-	if (!mPubThread)
+	if (!mPubLedgers.empty() && !mPubThread)
 	{
 		mPubThread = true;
 		theApp->getJobQueue().addJob(jtPUBLEDGER, boost::bind(&LedgerMaster::pubThread, this));
diff --git a/src/cpp/ripple/SHAMap.h b/src/cpp/ripple/SHAMap.h
index e7d4565588..6071603f58 100644
--- a/src/cpp/ripple/SHAMap.h
+++ b/src/cpp/ripple/SHAMap.h
@@ -413,6 +413,7 @@ public:
 	bool getNodeFat(const SHAMapNode& node, std::vector<SHAMapNode>& nodeIDs,
 	 std::list<std::vector<unsigned char> >& rawNode, bool fatRoot, bool fatLeaves);
 	bool getRootNode(Serializer& s, SHANodeFormat format);
+	void getNeededHashes(std::vector<uint256>& hashes, int max);
 	SMAddNode addRootNode(const uint256& hash, const std::vector<unsigned char>& rootNode, SHANodeFormat format,
 		SHAMapSyncFilter* filter);
 	SMAddNode addRootNode(const std::vector<unsigned char>& rootNode, SHANodeFormat format,
diff --git a/src/cpp/ripple/SHAMapSync.cpp b/src/cpp/ripple/SHAMapSync.cpp
index 344e2bdc1c..eb5e11b23c 100644
--- a/src/cpp/ripple/SHAMapSync.cpp
+++ b/src/cpp/ripple/SHAMapSync.cpp
@@ -19,7 +19,7 @@ void SHAMap::getMissingNodes(std::vector<SHAMapNode>& nodeIDs, std::vector<uint2
 	boost::recursive_mutex::scoped_lock sl(mLock);
 
 	assert(root->isValid());
-	
+
 	if (root->isFullBelow())
 	{
 		clearSynching();
@@ -91,6 +91,57 @@ void SHAMap::getMissingNodes(std::vector<SHAMapNode>& nodeIDs, std::vector<uint2
 	}
 }
 
+void SHAMap::getNeededHashes(std::vector<uint256>& ret, int max)
+{
+	boost::recursive_mutex::scoped_lock sl(mLock);
+
+	assert(root->isValid());
+
+	if (root->isFullBelow() || !root->isInner())
+	{
+		clearSynching();
+		return;
+	}
+
+	std::stack<SHAMapTreeNode*> stack;
+	stack.push(root.get());
+
+	while (!stack.empty())
+	{
+		SHAMapTreeNode* node = stack.top();
+		stack.pop();
+
+		int base = rand() % 256;
+		bool have_all = false;
+		for (int ii = 0; ii < 16; ++ii)
+		{ // traverse in semi-random order
+			int branch = (base + ii) % 16;
+			if (!node->isEmptyBranch(branch))
+			{
+				SHAMapNode childID = node->getChildNodeID(branch);
+				const uint256& childHash = node->getChildHash(branch);
+				SHAMapTreeNode* d;
+				try
+				{
+					d = getNodePointer(childID, childHash);
+					assert(d);
+					if (d->isInner() && !d->isFullBelow())
+						stack.push(d);
+				}
+				catch (SHAMapMissingNode&)
+				{ // node is not in the map
+					have_all = false;
+					ret.push_back(childHash);
+					if (--max <= 0)
+						return;
+				}
+			}
+		}
+		if (have_all)
+			node->setFullBelow();
+	}
+}
+
 bool SHAMap::getNodeFat(const SHAMapNode& wanted, std::vector<SHAMapNode>& nodeIDs,
 	std::list<std::vector<unsigned char> >& rawNodes, bool fatRoot, bool fatLeaves)
 { // Gets a node and some of its children