This sounds more like a file system problem than a CVS problem. If you set the group sticky bit on a directory, the files and directories that are created inside it will inherit its group ownership instead of being assigned the user's primary group. For example:
Code:
$ ls -ld /usr/local/cvsrepos/webs
drwxrwsr-x 8 cvs cvs_webs 4096 2006-06-04 07:59 /usr/local/cvsrepos/webs
$ ls -l /usr/local/cvsrepos/webs
total 40
-r-xr-xr-- 1 cvs cvs_webs 2287 2002-03-17 06:40 copyweb.bat,v
drwxrwsr-x 6 cvs cvs_webs 4096 2006-12-07 05:20 inflections
drwxrwsr-x 2 steve cvs_webs 4096 2006-02-12 05:32 monthly
drwxrwsr-x 2 steve cvs_webs 4096 2006-02-12 05:34 pricing
-r--r--r-- 1 steve cvs_webs 1705 2005-07-05 05:46 runsheet.txt,v
drwxrwsr-x 2 steve cvs_webs 4096 2007-10-24 08:30 steve
-r-xr-xr-- 1 cvs cvs_webs 4938 2002-06-02 05:10 webclean.pl,v
If it's any use, there's some info on this at
http://rute.2038bug.com/node17.html.gz