As segwit is active on testnet, blocks will only be downloaded from NODE_WITNESS peers. Though, exactly those peers are disconnected after `BLOCK_STALLING_TIMEOUT = 2` seconds. I am running master (6e6ab2c)

This behavior is consistent across restarts. Sample [debug.log](http://pastebin.ubuntu.com/23058327/) and [getchaintips](http://pastebin.ubuntu.com/23058325/).

It is possible that I shot my own foot at some point, but it seemed smelly enough to create an issue.

tx.GetHash().ToString(),
                mempool.size(), mempool.DynamicMemoryUsage() / 1000);
            
            set<NodeId> setMisbehaving;
            while (!vWorkQueue.empty()) {
                auto itByPrev = mapOrphanTransactionsByPrev.find(vWorkQueue.front());
                vWorkQueue.pop_front();
                if (itByPrev == mapOrphanTransactionsByPrev.end())
                    continue;
                for (auto mi = itByPrev->second.begin();
                     mi != itByPrev->second.end();
                     ++mi)
                {
                    const CTransaction& orphanTx = (*mi)->second.tx;
                    const uint256& orphanHash = orphanTx.GetHash();
                    NodeId fromPeer = (*mi)->second.fromPeer;
                    bool fMissingInputs2 = false;
                    
                    
                    
                    CValidationState stateDummy;
                    if (setMisbehaving.count(fromPeer))
                        continue;
                    if (AcceptToMemoryPool(mempool, stateDummy, orphanTx, true, &fMissingInputs2)) {
                        LogPrint("mempool", "   accepted orphan tx %s\n", orphanHash.ToString());
                        RelayTransaction(orphanTx);
                        for (unsigned int i = 0; i < orphanTx.vout.size(); i++) {
                            vWorkQueue.emplace_back(orphanHash, i);
                        }
                        vEraseQueue.push_back(orphanHash);