Media for Symantec Ghost across VLANS routed by cisco router

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.