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.

pool.CalculateDescendants(it, allConflicting);
                }
                BOOST_FOREACH(CTxMemPool::txiter it, allConflicting) {
                    nConflictingFees += it->GetModifiedFee();
                    nConflictingSize += it->GetTxSize();
                }
            } else {
                return state.DoS(0, false,
                        REJECT_NONSTANDARD, "too many potential replacements", false,
                        strprintf("rejecting replacement %s; too many potential replacements (%d > %d)\n",
                            hash.ToString(),
                            nConflictingCount,
                            maxDescendantsToVisit));
            }
            for (unsigned int j = 0; j < tx.vin.size(); j++)
            {
                
                
                
                
                if (!setConflictsParents.count(tx.vin[j].prevout.hash))
                {
                    
                    
                    
                    if (pool.mapTx.find(tx.vin[j].prevout.hash) != pool.mapTx.end())
                        return state.DoS(0, false,
                                         REJECT_NONSTANDARD, "replacement-adds-unconfirmed", false,