Corels (X5 and X7) freezes PC with Win7 but works okay in emergency mode

crashes in Windows 7 64 bit , so:  i have new PC with Win7 64 bit, and X5 started to crash when using "show overlay" (ctrl+H, ctrl+>+H), in XP it worked for years ,

so i downloaded new trial of X7, also crashes, so i tried to check it in Windows in "emergency mode" and ... it works - so due to this i found that something that causes crashes of Corel (rather not Corel itself, because it freezes whole PC) is within "normal" windows mode,

question is ANYONE KNOWS WHAT ?

difference is that "emergency mode" works without VGA drivers (i have 780 GTX Ti) , can crashes of Corels (both my owned X5 and trial X7) be caused by Nvidia drivers ? or something other wihin windows 7 64 bit ?

sory for terms - my native language is not ENglish, 

we call it mask, probably in ENG corel it is called "overlay, show object overlay, show mask overlay" 

so after "investigation" i see that crashes reported by people (i read forum since while) probably do not appear in "emergency mode" (i do not know how you call it in ENG)  (starting windows F8, than "emergency" or "normal" mode) 

so if it works in emergency mod (when OS doesn't load drivers) than ... than it must be drivers issue ? am i right?

X5 works like charm in XP

in 7 64bit not that charm, trial too, 

what can be responsible for it if not drivers from Nvidia ? i have newest drivers, i have update on windows etc. etc. etc. 

logic says "if software works without loaded VGA drivers, and freezes PC when VGA drivers are loaded than it must be fault of those drivers" ? (if am mistaken - than correct me please, but afair in emergency mode OS loads only basic drivers and no graphic card drivers )

can Corel check (X5 patch would be welcome  than) what happens with Nvidia drivers (i repeat i have 780 GTX Ti and it is not issue of missing memory or other suff, PC is very powerfull and big and lots of fans SSD, i7, 32 GB memory, it is not laptop but big desktop)

or you know other differences of win7 vs corel ? 

it freezes PC especially when object is made of thin lines objects (like UV layer  for texture for 3d model - on this example , UV of mesh of 3d soldier in uniform)

can it be responsibility of large monitor ? 2k or 4k?