That's the problem w/ dual Opie+GPE images. If you are in Opie, GPEs powersafe deamon "ipaq-sleep" will shut down the display since the X11 session is idle. If you are in GPE, Opies powersafe functions will do the same.
A work-around would be to disable screen blanking in both GPE and Opie.
It is one of the annyoing things stopping me to release combined images for download (there are some more however, like non-working SDL (3D rendering) in one of the two GUIs)