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.

{
    if (!pindexBestInvalid || pindexNew->nChainWork > pindexBestInvalid->nChainWork)
        pindexBestInvalid = pindexNew;
    LogPrintf("%s: invalid block=%s  height=%d  log2_work=%.8g  date=%s\n", __func__,
      pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
      log(pindexNew->nChainWork.getdouble())/log(2.0), DateTimeStrFormat("%Y-%m-%d %H:%M:%S",
      pindexNew->GetBlockTime()));
    CBlockIndex *tip = chainActive.Tip();
    assert (tip);
    LogPrintf("%s:  current best=%s  height=%d  log2_work=%.8g  date=%s\n", __func__,
      tip->GetBlockHash().ToString(), chainActive.Height(), log(tip->nChainWork.getdouble())/log(2.0),
      DateTimeStrFormat("%Y-%m-%d %H:%M:%S", tip->GetBlockTime()));
    CheckForkWarningConditions();
}
void static InvalidBlockFound(CBlockIndex *pindex, const CValidationState &state) {