Make sure you have no .x11amp directory in your home
directory. Invoke x11amp and select a level 3 mp3
file to play, it will dump core.
The problem is that x11amp is not setting itself up
correctly with various defaults if no ~/.x11amp/config
So if you start x11amp, and then exit it, x11amp will
create a default ~/.x11amp/config file and this problem
goes away for all future invocations.
The core happens because the mpg123 library is being
passed a null pointer for the ip3_format argument in
seems to have been fixed in 0.9_beta1.1