After buying the Office 2007 version I started to experience a lot of crashes in Excel 2007, especially when closing workbooks and opening new workbooks. After each crash I found something like this in the Application Event Log on my laptop:
Faulting application EXCEL.EXE, version 12.0.6331.5000, time stamp 0x48fa2869, faulting module OLEAUT32.dll, version 6.0.6001.18000.......
Since I in the past has experienced some trouble with "clever" addins, I removed every addin that was active in Excel. After this I used Excel for some time without experiencing any problems.
Then I started to add the uninstalled addins one by one, using Excel for a while before I added another one, until Excel started to crash again.
When I finally found my "suspect", I uninstalled all addins again, and confirmed that Excel worked like a charm again. Then I added only my "suspect" addin, and Excel got straight back to its frequent crash behaviour again. That was enough for me to find the "suspect" addin guilty of bad behaviour,and this addin is no longer in use on my laptop.
If you are having the same problems with frequent crashes in Excel, you might want to try to uninstall this COM addin: Send to Bluetooth (btsendto_office.dll).
Since the Excel application did not allow me to uninstall it from the user interface, I had to do it in the Registry Editor:
Find the key LoadBehavior and change it from it’s current setting (normally 3) to 0 to disable the addin. When you start Excel again, the troublesome Blutooth addin should be gone, and the frequent crashes too.