I'm experiencing a bizarre thing when Excel calculates large spreadsheets (Excel 2003. Windows XP.).... when it calculates, it LOOKS like it's actually cycling through each of the pages as it calculates. Then, when it's done, I'm left with what LOOKS like bits of each page it touched on my screen. I can scroll way down, so the previously visible part of the screen disappears, then scroll back up, and the mess is gone and I can see what's ACTUALLY on my page.

This is happening in reports that I've been running for ages with no issues like this.

What HAS changed... is that my computer has been re-built in a new spec (thanks to a company merger, we've all been re-built). I still have the same amount of memory, etc. But there are some differences in the way Windows behaves and the permission settings. The problem is I don't really know EXACTLY what they changed.

Has anyone ever seen this before? Any clue what they could have changed - a setting somewhere in Windows maybe - that could cause this to happen??

To get it fixed, I have to go to them with a solution - I can't just say 'it's broken', that won't get me anywhere!