Losing sound from AIM

[BMdoobieW]

I'm having a problem with AIM. I use AIM (4.8.2646) with the add-on thing "Aim+" and I run WinXP Pro. I leave AIM on all the time, and usually after a few hours, I stop hearing sounds in AIM...such as when I receive an IM. If I go to the preferences and choose "sounds" and pick a sound (wav file) and hit "preview," I hear no sound. But I can play the same file in Winamp and it works fine. Usually I'm also running Windows Messenger, Eudora, Kerberos, and Norton. The sounds in all other programs continue to work. Anyone know what the problem might be? Thanks.