If two sessions of Excel 2007 are open - each with one active workbook open
in each session, copy and paste will only work a handful of times and then
will not paste between the workbooks. By having two sessions of Excel open -
I'm referring to starting Excel twice and having a workbook active in each
version. The only reason why I could see anyone doing this is to avoid
trading range names between workbooks ....

However, if Excel is started and both workbooks are in the same session copy
and pasted doesn't have this problem.

The file size of the workbook are not huge 1M on one and 3M on the other.
No macro's on either workbook - pivot tables are used extensively (deleted
the sheets that had the pivot tables - same problem still occurred.)

It didn't apprear that the clipboard was full.

Looked to see if this was a known error - could not find any documentation.
Any idea's