We've been getting some strange errors on an Excel VBA project:

On random computers, it stops on random lines as if at a breakpoint,
but there is no breakpoint there; in fact it sometimes happens when a
non-programmer just opens the Excel file and clicks a control to run a
macro. Since VBA doesn't save breakpoints, it obviously isn't a real
breakpoint.

It isn't stopping on an error in those instances, because once it
stops like that, it will happily proceed without error if you simply
press F5.


On the same project, we've also been getting random bogus compile
errors, as if a referenced variable, form, etc. did not exist. Once it
even did it on Excel VBA's built-in Right function, as if Excel VBA's
Right function did not exist. But if we copy the workbook to another
computer, or try again later on the same computer, it runs without
error.


I'm guessing workbook corruption, but is there anything else I should
be looking at too?

Here's what I tried just now:
-- Copied all worksheets to new workbook.
-- Added the required references to the new workbook.
-- For each module and class module, copied text of module into
new module.
-- Copied code behind workbook module.
-- Copied all forms.

I'm doing most of the development in Excel 2007, and users are mixed
between Excel 2007 and 2003. On previous projects, I've also seen the
random phantom breakpoint problem on a project done only in Excel
2003.

Any other suggestions?


Thanks,

Greg