Some files don't show info balloon on hover Windows 7

Hey all. We recently got a new computer with Windows 7 Home Premium and I'm having a small issue with it. When hovering the mouse on some files it doesn't show an info balloon. The files are Macrium Reflect images, PDFs and PowerPoint files. Word files and most others I've tried work okay though. I do have ownership and full control of the files I've tested. Can anyone think of anything else that might cause this? It shows info balloons fine on all the folders I've tried, only issue seems to be certain files. Appreciate all suggestions (except use Details view ). I use medium icon view.