Welcome to Seven Forums nobody123r. That is an odd problem, and not one I have seen before. It may be graphics related, or just explorer related. Until others reply with more ideas, I have a suggestion. It will be easier then restarting your PC if it corrects the issue. Next time it happens, restart explorer.exe
You can do it manually, but I have added restart explorer.exe to the right click context menu using Brinks tute:
Explorer - Add "Restart Explorer" to Desktop Context Menu
You can also open task manager, right click on explorer.exe and choose end process. Then open task manager again. Click on file in menu upper left. Choose new task, and type in explorer.exe
It's just much easier with the shortcut, and very handy on occasion. Let us know how it goes. This doesn't fix the cause, but may help us diagnose it, and save you some trouble.
A Guy