All things related to multicast

Hi,
        I have a question on what should be expected behavior for 
PIM/IGMP.

I have a source which sits behind two switches that are running vrrp. 

Switch A IP: 10.1.1.9
Switch B IP: 10.1.1.10
Virtual IP:      10.1.1.11.

I also have some users that are directly connected to Switch A, and Switch 
B.  For some odd reason all users that are connected to Switch A can 
receive the stream.
Everyone connected to Switch B cannot.  The funny thing is that if I 
single home the same source onto switch A it works fine.  If I single home 
the src to Switch B it works fine.  The only time it has issues is if they 
are in this VRRP configuration.

Question: 
Because Switch A is the IGMP designated router, does that mean Switch B 
should stop responding to any requests for that Group? even though its 
directly connected to that group? 

Or is this another Bug?  Both switches are Nortel 8600's.

Thanks
Anand