mask marqee visible overlay cause PC freeze

I have such problem but get no answer , I updated my old post but it was deleted as "abusive" (do not know why moderator deleted my problem )

So : 

i have strong PC, Nvidia 780 GTX, Windows 7 64, a lot of memory etc. 

i have X5 , i tested X7

it freezes PC when i use "marquee visible" on thin lines objects/layers

i work on making textures for models - as someone knows 3d modelling - model has mesh, this mesh has "UV mapping"

so normal job to paint textures for models - when you use UV map mesh

but Corel freezes PC when i use "marquee visible" , it simply freezes PC (do not tell me to update drivers - i know such things - i have all up to date)