during the past 2 years have you re-installed ur OS in any of them?
if u havent, then i guess something is wrong with the ur OS (or maya's) processes/services ... if u have, then it must be one of the software u have installed beck then and now,
its best if u do a fresh install of ur OS and install maya as one of the first softwares (if u hadnt tried it allreasy ... might be conflict with another software)
i don think its a hardware/driver issue as ur experiencing this in 2 different systems ...
it might be a VGA driver issue too (if both ur systems has the same VGA)