atd trouble

[progoth]

ok so I compiled gentoo today. I have x, kde3, usbmouse, sound, etc all
working great. I installed atd, it's running, I type this:

~ at 23:55 <<C
/usr/bin/mpg123 ~/alarm.mp3
C

the job shows up with 'atq', and when the time gets here, the job is
removed. however, it doesn't seem to be run.

if I type mpg123 ~/alarm.mp3 at a console it works fine

any ideas?