DOSBox on the BB

I'm having problems with DB's fullscreen mode on my BB.
It simply doesn't work. Alt+Return crashes the program and
changing the config file settings fullsreen=false to
fullscreen=true results in DB not even starting.

I entered the native resolution (1024x768) at the
fullresolution line but that didn't help either.

I do know however, that DB runs fine in fullscreen mode
on other peoples BB so it's certainly not impossible.

Patric
.