Got a bit of a wierd problem when using Excel 2003.
The user has 3 or 4 different sheets open, as well as other applications, word, IE, 3rd party DB application.

At random times, suddenly the user will switch to excel to work and all the cells and text/numbers within the cells is massive (like font 80 or something) and the sheet is completely unreadable. the windows are still operating and you can switch between apps and between excel sheets, but you can't get the graphics back to normal.
The user has to close the sheets and then excel crashes (send error report?) and then you can reopen the sheets and carry on.
I have never seen anything like this - it doesn't seem like graphics card error, as all the other windows and apps behave normally.

Don't know if it is excel corruption or what else to consider - have already reinstalled office!