Transactions not showing up in bitcoind log? I have a bitcoind running on a server behind the www box which I poll every minute for new transactions and save new data into a table. 

Something strange is happening sometimes. If i send 1 btc from my wallet to an address on the bitcoind server, it gets through just fine and shows up right away in the log when downloading transactions via RPC.

If however I send from an exchange, it does not show up (at least not for a day or two). I've noticed that these exchanges add another address and amount to the same txid, could that be the cause? 

Is there a workaround for this?

TIA
Use walletnotify instead of polling. 

how to do address callbacks?

It's basically a argument you can specify and Bitcoin will the specified program upon receiving a transaction (BOTH receives and sends from an address in wallet get notified). So you just setup a small script to run and point to it in bitcoin.conf.

Be sure to check for duplicates as walletnotify sends notifications for when a txn is first received (unconfirmed) and when it receives a confirmation.

Also blocknotify does the same thing as walletnotify but for blocks, may be useful for checking unconfirmed transactions.