Our department creates macros with VB (mostly in Excel)
and sends them to users across the country. Occasionaly,
we have users who have used these macros for months
without any problem and then all of sudden they get an
error message.

Most of these problems seem to occur with the Left and
Right commands. They work for a long period of time.
Then all of sudden there is an error. When we debug the
issue, the highlighted word is Left or Right. We have
begun using Mid instead and this doesn't seem to happen as
much.

(It also sometimes happens with "Cols". When we
substitute Range for Columns the issue doesn't seem to
happen as much also.)

Following is an example of code we have used for months
without any problem.

YR = IIf(Dorder = 2, Left(Dtext, 2), Right (Dtext,2))

All of sudden some, but not all, users have started
experiencing a "Compile Error: Wrong number of arguements
or invalid property assignment".

Has anybody experienced anything like this before? What
causes this issue? Does a different machine setup (e.g.,
version of Excel, etc.) have any affect?

Any information you can provide or if you can point us to
any reference material to resolve this would be
appreciated. Thanks for the help.