I am experiencing the same thing. I have 1.5 G of memory and have checked
that there is plenty available.

The only thing I can add is that I am using a tablet PC, often use
Hibernate, and sometimes change screen orientation between portrait and
landscape.

This issue requires a reboot to clear up- not always an option.

This is a bug that needs fixing...

"brad" wrote:

I get this message when I leave Excel 2007 idle while I am in different
applications. When I switch back to Excel 2007 I occasionally have this
problem even though my computer has 2 GB of memory and I don't have hardly
anything else running. Does anybody know what is causing this? I never had
this problem with the previous versions of Excel.