[Evolution] Strange CVS behavior???

[dan hensley att net]

Something I've noticed recently that really bugs me is
what happens when I do a cvs -z3 update.  If I do it
once, it usually syncs up any recent changes.  But if I
do it again not long after, it appears to revert all the
recently updated changes.  Why is this?  I notice it
mainly with Evolution, because that's what I update most
often.

Dan