Not inside of any game or anything, but inside the editor itself. I have recently upgraded to 3.1 and started experiencing this issue.
This has naturally rendered the entire editor completely unusable. I am running Windows XP sp3, and Unity 3.1. Note: I have had Unity 2.6 installed prior to this without the issue.
Don't know if it can be changed but have you submitted this as a bug. That would be the first thing you should do.
Until you have a fix of some sort, go back to 2.6. Make sure you uninstall everything (also delete the program folder) before installing 2.6 if it's not fixed.
The problem was really just my own stupidity all along. A recent reinstall of XP somehow turned off Cleartype.
We are aware of problems on some older Intel embedded GPUs. Something you should try (whatever GPU you have) is to update to the latest graphics driver. The screenshot in the question shows that the GPU is rendering textures for each character in the inspector window, but the textures are corrupt. This often points at a GPU/driver problem.