Status message on Yahoo Messenger

[Nightbright02]

I can't figure out why my status message is being reset to "available" without my permission. I could walk away from the computer for 2 minutes and all of a suddent it says im "available" even though I just put up my status message as "away from my desk". I could see if they were somehow disconnecting me but then I would think they would sign me back in as invisible because thats my default; this isnt happening. How do I stop this from happening?

Oh and in addition sometimes when this happens and I will be in the middle of a conversation the person im talking to doesnt get any of my messages. They see me as online and connected but they dont get my messages for a certain amount of time.
CAN ANYONE HELP ME????