Custom Toolbar Button Problem

I've been having a problem with some custom toolbar buttons I've created and I haven't been able to find a cause or solution on the web. I have created a few simple macros to do tasks that Excel doesn't have built-in toolbar buttons for - an example would be a button that fits to one page for printing. This macro (and the others) are saved in an add-in file called Buttons.xla that is added into my Excel.

The problem is that occassionally (and apparently randomly) these buttons will begin targetting a file other than my .xla file to find the macros. When I click on the button after this occurs, I get an error message that the macro can't be found. When I edit the custom button, the macro will be listed something like this Book1.xls!fit_to_page. If I delete the 'Book1.xls!' portion and save, the button will work fine for a few days, a week or a month before switching back to some random file.

I know this is confusing, but anyone have any ideas? Thanks for your help - Chad

I had a different but similar issue. I had a file say myMacros v1.xls where that had macros pointing to my custom toolbar. When I upgraded to myMacros v2.xls and distributed it to others, the buttons kept pointing to the v1. Different cause but same problem. I solved this issue by adding an auto_exec macro as follows

Sub auto_open()
Application.CommandBars("myToolbar").Visible = True
Application.CommandBars("myToolbar").Controls("myButton").OnAction = "Macro1"
End Sub

The macro reasigns the buttons to the correct macro each time the file is open. Not sure if it will work with an XLA.

Matt