Desktop Picture slowly obstructing open apps

A friend of mine has a HP G62 notebook with Windows 7 Home Premium x64. The machine runs fine for the most part, but she is stating that the Desktop Wallpaper picture that she has for her background slowly morphs into view while she is working in either Word or when she is in Gmail. It will then obscure what she is working on, yet she states she continues to type, and then the picture fades back to the desktop and her Word or Gmail application is still there with all of the information that she has typed into the program.

These are the only times this happens.

Now I've gone through all of the settings in power options, in the Personalization area, etc. I have had the computer open infront of me with my own gmail account and word open while i work throughout the day and not a single time have I been able to reproduce this scenario.

Can anyone give me any ideas here? I hate taking the machine back to her and stating there is nothing wrong when this has been going on for several months now. Admittedly the skill level of the user is novice at best, but I am taking her word for the situation.

Any help or ideas will be greatly appreciated!

Thank you!

Have you checked the graphics driver? Try reinstalling or updating that.