This is all a bit odd. I'd expect the screen stuff to work fine unless:
a. you're running a wireless network or
b. you have the same ip address assigned to more than 1 receiver or
c. your server machine spec is quite old (p166 or the likes)


When the trio server sends screens to the receivers, it only sends what's changed (to save bandwidth). My guess is that these are either arriving out-of-order or being lost. PM me your email address and I'll send you a version that sends the full screen every time (not just what's changed) and we can see if that fixes your problem.

Cheers
Paul