"Out of Memory" message Excel97 - 11meg file

A co-worker has an 11-meg file - 30+ sheets, charts, 3-D formulas etc.
She is starting to get an "out of Memory" error when doing such simple things as formatting text - no other apps are open.

The file is stored on a network drive, and the app is pulled off the network as well.
We've tried working with the file on a couple of Pentium & PEntium II's with 32-64 meg memory - same error.

We've cleared the C:\Windows\Temp file and made sure the formatting is not extending beyond the data.
We're also looking at changing the Zoom to 100%.
The file does have macros - I have not gone into the code to see what is going on there yet.

Any thoughts on what might be causing the problem other than maybe the file size?

Thanks!
Tracey Morris