Can anybody help me, or shed any light on a very frustrating error I am receiving from Excel (2000, SP3)

The message I am receiving is 'Excel has generated errors and will be closed by windows, please close and restart' An error log is generated and the spreadsheet is closed.

This only happens when I open a custom spreadheet I have designed (with quite a bit of VBA behind the scenes)
The message seems to only appear when I close the spreadhseet and click 'No' when it prompts me to save.

Does anybody have an experience with this type of error? or can anybody point me in the direction of the saved log?

Any help is appreciated!
Ben