There were 3 questions. If you have a firewall enabled, try disabling it to see if that gets it to work. If it does, then you know that you need to focus on what exceptions you will need enabled. If you can ping and have file and print sharing enabled, then you will want to check the AClient/DAgent (whichever one you are running at the client level).
How is the client set to find the DS server? Multicast, IP, or ??? Ensure that settings here are correct for your environment. Also ensure that the AClient/DAgent version matches the DS version. I believe the DS 6.9, SP1 is 6.9.355 (not positive though). I am currently at 6.9.366.