I have an application that references a dozen or so procs in my Personal.xls. One of these procs (let's call it Function A) was giving incorrect results. I added a few debug statements to it, but the debug outputs did not appear (actually, I used MsgBox). So I copied A out of Personal.xls and into the target application. The debug statements now appear and the results are correct. I copied it back to Personal.xls, deleted the version in the target application and was back where I started, i.e., incorrect results and no debug statements.
I then renamed A to AA, changed the call in the target application and ran it again. This time everything worked.
So either there is a bogus version of A floating around or A is some special reserved/illegal name. I have searched for A and can not find another copy. The function has been "in use" in multiple applications for several years.
Any ideas?