I have just gone through this with my Cingular x497. It is a new phone, hence some of the problems. Also, the folks selling these serial cables on ebay don't seem to know that the cables and the software for Samsung are model or series specific. I bought one which was advertised as for the x497. After speaking with the good folks at Samsung, I learned that botht he cable and the software were incorrect.
The ebay vendor has offered a refund, but I'd rather have the correct items.
Another suggestion, buy Samsung accessories whatever you are going to connect to your phone. I connected a generic hands free set, and it disconnectd every call!
Susteen makes a great app called DataPilot, (
http://www.datapilot.com/), but they don't support the 495/497 yet, although their website says it's coming soon.
Good luck.
Partymonster