Mmsytem error on lossy formats

I've been encounter a few random MMSYSTEM (Microsoft System APIs for Multimedia) errors from Winamp on Win98. When I close Winamp after listening to mpc's, mp3's, and ogg's I'll randomly receive an MMSYSTEM dialog, especially after I've ripped a ton of CD's in EAC. I replaced MMSYSTEM.DLL, yet the problem is still persistent, and so far I haven't been able to remedy it.