Sorry - I use Q&A 4.0
but don't even have a printer hooked up, so haven't tried to print with dosemu.
If you've got printing working, it sounds like a dbase issue. Q&A (completely different, I know, but still...) has a printer/port/model definition. I guess just make sure dbase is looking for lpt1 and isn't trying to do anything fancy with it.
and the rest of the thread will help? Or other stuff at google/linux