Invalid page fault

When one of my users tried to access the source data, from a graph in Excel, they get an ‘Not enough memeory’ error message. When you OK this message, the illegal operation box comes up. When I click on the details tab, the following comes up….
‘Excel caused an invalid page fault in module excel.exe at 0137 : 30126e9e

This problem is starting to get the better of me, so any help would be appreciated

Ragards

Neil Hughes