When saving an Excel file the program crashes

We get the following error saving a Office 2007 Excel file. Have no clue why
we are getting it. Any help would be greatly appreciated!

Log Name: Application
Source: Application Error
Date: 10/8/2009 9:56:59 AM
Event ID: 1000
Task Category: (100)
Level: Error
Keywords: Classic
User: N/A
Computer: TERMSVR.hillcrestnh.org
Description:
Faulting application EXCEL.EXE, version 12.0.6504.5001, time stamp
0x49fea693, faulting module EXCEL.EXE, version 12.0.6504.5001, time stamp
0x49fea693, exception code 0xc0000005, fault offset 0x004792eb, process id
0x3934, application start time 0x01ca48276521cae8.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Application Error" />
<EventID Qualifiers="0">1000</EventID>
<Level>2</Level>
<Task>100</Task>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime="2009-10-08T14:56:59.000Z" />
<EventRecordID>59868</EventRecordID>
<Channel>Application</Channel>
<Computer>TERMSVR.hillcrestnh.org</Computer>
<Security />
</System>
<EventData>
<Data>EXCEL.EXE</Data>
<Data>12.0.6504.5001</Data>
<Data>49fea693</Data>
<Data>EXCEL.EXE</Data>
<Data>12.0.6504.5001</Data>
<Data>49fea693</Data>
<Data>c0000005</Data>
<Data>004792eb</Data>
<Data>3934</Data>
<Data>01ca48276521cae8</Data>
</EventData>
</Event>