Ken,

It seems to me if you're getting the error at aryInvDetail(indx, 0) then it may have something to do with the function you're sending it to
GetExpTypeID(aryInvDetail(indx, 0))

Do you by chance have the argument for that function to be a ByVal? Array items have to be ByRef, if the function is expecting ByVal, you'll error out.

Matt