The total transaction count (for progress estimation) is counted as the known count at the last checkpoint, plus an estimated number per day.

The last checkpoint is now 996 days ago, and its estimated 60000 transactions per day leads to a total estimate of 96M transactions, while the real number is around 183M.

Fix this by updating the count, timestamp, and rate of transactions... with or without adding a new checkpoint.
{
    uint256 hash = wtxIn.GetHash();
    mapWallet[hash] = wtxIn;
    CWalletTx& wtx = mapWallet[hash];
    wtx.BindWallet(this);
    wtxOrdered.insert(make_pair(wtx.nOrderPos, TxPair(&wtx, (CAccountingEntry*)0)));
    AddToSpends(hash);
    BOOST_FOREACH(const CTxIn& txin, wtx.tx->vin) {
        if (mapWallet.count(txin.prevout.hash)) {
            CWalletTx& prevtx = mapWallet[txin.prevout.hash];
            if (prevtx.nIndex == -1 && !prevtx.hashUnset()) {
                MarkConflicted(prevtx.hashBlock, wtx.GetHash());
            }
        }
    }
    return true;
}
/**
 * Add a transaction to the wallet, or update it.
 * pblock is optional, but should be provided if the transaction is known to be in a block.
 * If fUpdate is true, existing transactions will be updated.
 */
bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate)