I've got this issue myself. I've seen this mentioned at avsforum and after reading a few posts of people with this issue I got a clue of the cause and have verified it and I wish CyberLink would fix it as it's been around awhile. So here's the bug CyberLink (now please fix it):
In a multimonitor system if one of the monitors (I'll detail my setup below) is in portrait orientation you get this bug.
I can't say for certain if the rest is important (but in case it is):
My setup (that generates bug) Monitor 2 is my primary monitor it is in Landscape mode at 1920x1200. Monitor 1 (to the right of monitor 2) is in Portrait mode 1200x1600.
Workarounds:
Switch Monitor 1 to Landscape.
Disable portrait monitor.
It's a real pain to have to whack my second monitor to use PowerDVD. I also am totally confused as to why this check is even in the software cause it can and by default is ran in a window anyhow. Please fix. If I can be of assistance in testing I'd be glad to.
My one other (after just having installed program) complaint is that in Win7 it exits Aero when running PowerDVD10Ultra.