Do I understand this correctly?

There is one sheet A, so if function one() opens sheet A, then calls
another function two() which also opens sheet A, there shouldn't be a
problem. Right? When two()returns, one() should still have the same
"handle" to the sheet and should still be able to work with it.

But something is up. VBA is losing its brains somewhere. All of a
sudden simple range assignments fail on sheet A, but also on other
sheets. If I try and investigate and expand the sheet expression in
the Locals window, Outlook tries to install! If I just go ahead and
ignore the error (hit continue) everything seems to work just fine.

Again, about instantiating multiple "handles" on a single sheet. That
should be ok? (I'm not 100% that this is causing the problem, but
first things first.)

Thank you

Xcel 2010, xp