Excel 2010 - copy/paste is broken - help

[bab01824]

I can't figure this out. I am running MS Office 2010 Pro. In MS Excel I have lost the ability to copy from one worksheet into another. What could be causing this? It's becoming a real pain in the, ummm, keyboard!
Bruce B...

 

[GruPatrick]

How are you trying to copy and paste, CTRL C & CTRL V?

 

[p45cal]

Is there any event code working in the background?
Are the sheets in the same workbook?

 

[bab01824]

It doesn't matter how I try, through the menu, right-click, Ctrl-C,V, Shift-Insert, etc. It seems that the FastExcel Addin I'm using may be the culprit because when I de-activate it the problem goes away.