Set CVS to Ignore Case as a File Difference Upon UPDATE

I am trying to use CVS (specifically WinCVS) to manage a VB6 project.
VB6 has the annoying problem of changing the case of variables across
many files without warning.  This leads to many files being out of
sync with CVS when the only difference is the case of variable names.

I know that the cvs diff function can be set to ignore case and white
space changes.  However, this doesn't really help when I cannot set
cvs update to ignore the same things.

What am I missing?  Does CVS support ignoring case-only changes in
files?

Thanks.

-- Gary