I just tried this: I created a form with a text field and two command buttons with the form's background green and I do not get any trouble printing. I did change a few lines.

Set console off
set printer to \\server\hplaser
set device to print
....

set device to screen
set console on
set printer to

I hope this helps. Past that I wonder if you have some sort config or device driver problem. Try this program on an different computer.

John Fabiani