Since you are using Cacko, I assume this is for xmms-embedded. If memory serves me correctly, this program was never optimized for the 640x480 display. Even when I had a 5500, I never really got used to the xmms-embedded user interface.
If you are trying to play music under Cacko, the sharp music player works fine for mp3 files, and kino2 can play ogg's. You could also install meanie's pdaxQtrom packages and get the real xmms -- in which case the Ctrl-D technique to double the size (as others have described) should work.