Are you using embedded albumart? This has never ever happened to me, but I only use cover.jpg
define 'embedded'. I use MP3tag app to add track data (titles, artists, year, composers, etc. and the
add cover function) to an audio file. Most covers are jpg, though some are pngs. Image format should not cause this issue. This release is the first time in WACUP/Winamp history that I have encountered this.
Today, album art was blank when a new set of audio files were loaded for playback into WACUP. Two pressing of 'x' seems to be the best (annoying) work-around.