Workbook Sometimes Doesn't Find Macro in Another Workbook

[klem_is_me]

I have a workbook that has a macro in it that other workbooks access. I find that sometimes when I open another workbook which doesn't contain the macro and try to run that other workbook's macro, sometimes it finds it and sometimes it doesn't.

Details: The main WB that has the macro is open and has a hotkey associated to it (CTL-k). I receive many workbooks (w/o macros) as attachments to Outlook messages. I copy the attached WB to the desktop and then open it as Excel. I find that if the WB opens quickly (they are small and all about the same size), I can hit the hotkey and the macro runs. If it opens slowly and I hit the hotkey, the macro doesn't run and in fact opens the default action for CTL-k (hyperlink) and if I click macro on the ribbon, there is no macros listed.

I can close that WB I opened from the desktop and reopen it and it will open quickly and run.

Any ideas on what I'm missing? Thanks.