'vc-next-action' shows incorrect result, but 'vc-print-log' shows correct result.

[ChristopherMBalz]

Under Gnu Emacs 21.3.1 on WinXP SP2 with cvs, the 'vc-next-action'
command results in a message that a file is up-to-date, when that file
is in fact not up-to-date.  But 'vc-print-log' shows the correct log
(the comments entered with the changes, etc) file from cvs.  There's no
findable documentation on how to troubleshoot or avoid this situation
(assuming it's not a bug).

Any ideas?  

Thanks in advance.