Thats the problem, i got it to work by reading from this community and added the lines "ip pim sparse-dense" to all vlan related interfaces.
Now my problem is that my symantec ghost sessions went from approx 5 -
7 minutes to now 20 - 30 mintues.Thats unacceptable as anyone can see. What has gone wrong and why would this occur if my router is 2821, which has dual gigabit ethernet ports.
Thanks for your time.