Windows 2003 / ZCM primary server is not refreshing in the ZCC

If i manually refresh the agent it appears to work, but the last refresh date does not change, the last contact date changes as normal. I have tried clearing the cache and restarting the primary server and services

I cannot see anything of significance in the logs, all the managed devices are also showing the same last refresh date as the primary server which is over 2 months ago!!!

any ideas