sep client upgrade issue from 12.1.2 to 12.1.6

Hi All,

I have pushed upgrade package of sep client(12.1.6) at a few machines(having OS Windows server 2003/64 bit). I am upgrading their sep from 12.1.2 to 12.1.6. I have done this from SEPM console by pushing the upgrade package from the "Add client install package". But, even after 8 hrs. client has not been upgraded. When I see the client status from sepm console, it shows "the client has accepted the sep 12.1.5XX" in deployment status, but at the client end it shows the same earlier version i.e. 12.1.2. Please suggest any solution.

Thanks in advance.