I have a custom Excel 2007 Tab, deployed in an XLAM add-in file that works as
it is supposed to in other regards, but disappears when editing the XLAM file
itself (i.e., the ThisWorkbook IsAddin property is changed to False) AND then
Switching Windows to another Excel file. If I switch back to the XLAM file,
the custom Tab re-appears but then disappears again when I switch back to
another file besides the XLAM. When the XLAM ThisWorkbook IsAddin property
is changed back to True, the custom Tab is then again visible even with the
same file that it was previously not visible with when editing the XLAM
file.

I'm hoping someone might either have some insights into to either how to
prevent this from happening or perhaps suggest a macro to correct it if it
can't be prevented.

Thanks!

Jeff