Visual bug while opening packs

Hello. I’m having annoying visual bug while I drag and put the pack during the opening process. It disappears for a moment, then appears back. I’ve had this before Saviors of Uldum expansion start and its still there…

This is how it looks like:
i.imgur.com/ryQqqI7.png

i.imgur.com/RpQhrO0.png

i.imgur.com/yiLjd6q.png

How can I fix this? Is it a known issue? Please help, I want to open Descent of Dragons packs comfortable.

OS: Windows 7 x64

Thank you!