Why does foobar stop & display

I just purchased a Wyred 4 Sound DAC II, and play FLAC files off a PC with Vista OS via WASAPI and foobar (using USB). Most every time I play a playlist, after 3 or 4 tracks, foobar will stop and display a "too much buffer" error. I can close the error message and continue, but changing the buffer settings on foobar doesn't fix the problem. Does anyone know what can be done?
Thanks