Option Explicit is at the top of the comm module where the code
appears (as well as others) but not all modules.

On the "auto Variant" vs. Dim error, neither happens. This module
has Option Explicit in the Definitions and if I run the Sub, the vars
what are on the left of an = sigh, always =0 -- no error. Wierd. I
asked serial  I/O questions on code  Guru and wrox.......

So... Option Explicit forces definitions in the current module only...