Has anyone encountered connectivity problems when it comes to yahoo and using the phone on the 8700?

Here's my situation; whenever I am on the phone, say for @ least 10mins, and I go into the yahoo chat program, it says that I am connect.But wen I send a message to someone, an error messages comes up saying yahoo has unexpectedly lost connection; and its only then does yahoo re-connect.

So as long as I don't touch the YIM when I get off the phone, it stays disconnected.
Has anyone else experiencied this?

Yes, that's normal. Yahoo has a short timeout period and will log you off automatically after either 5 or 10 mins (i forgot which). It is normal though.