Client not reporting to Symantec endpoint protection manager

I have a SEPM server version 11.0.3001.2224, all the clients are version 11.0.5002.333; the server and clients are updating correctly. The problem I am having is that the clients are not updating to the SEPM. As it can be seen from attached file 'Virus definitions distribution' the definitions is still on 2011-06-30 though the clients are uptodate. When I check Clients, the Antivirus Status column shows 'Not reporting Status' as per attached file.

How can I solve the problem? I also need to update the SEPM to the latest version 12 RU2; can I upgrade the SEPM 11.0.3001.2224 directly to 12.1.2?

Any comments most welcomed.

Thanks.

Arvind