I guess I'll chalk it up to experience at this point. It seems that there might be someone else that had a handle on one of the private keys in an old wallet address of mine. I had transferred 2.29 BTC from an online fund to a wallet address (137XxRSiYRTB8PyGvEjjz5vZsd7oSNbdbE). After it received a confirmation, I end up seeing another transaction I didn't approve of sending those 2.29 BTC over to 1J8KsZqj8qWWUSqH2bmQHTTEm1xdNLY7AZ.
Not sure how this managed to happen, though I'm not too happy about it at this point. I've marked the wallet never to be used now. Not really looking for a solution unless anyone knows who or how it may have happened, but it sucks to see bitcoins disappear like that especially at the current valuation...