problem while checking out a file

[Jaya Kumari]

Hi all,
        I have a system user and cvs user with the same name.
And i have a group CVS with users who can access the repoistory.
I have changed the group of the repoistory folder to CVS.
When i try to checkout a file it is giving me the following error.

cvs checkout -P uClinux-dist/config.in (in directory C:\)
cvs checkout: Empty password used - try 'cvs login' with a real password

cvs [checkout aborted]: authorization failed: server 172.16.12.152 rejected
access to /opt for user ssatya

ssatya is a user in the group CVS.

the folder permissions are as follows :
drwxrwxr-x    3 rtslinux CVS          4096 Nov 14 19:56 CVSROOT
drwxrwxr-x   17 rtslinux CVS          4096 Nov 14 20:10 uClinux-dist

the /etc/group file has the following entries :
rtslinux:x:501
ssatya:x:503
CVS:x:505:ssatya,rtslinux

not able to figure what is the problem.