Help REP ring topology configuration

[clark72]

Hi all,
I have four switch 3600 and two switch 4500.
I configured two ring with rep protocol, ring10 and ring 11.
Every ring is composed by two switch 3600 and the two 4510 that are configured in redundant mode with hsrp protocol.
On every switch 3600, in addition to the ring vlan is configured another vlan:

vlan 30 and vlan 20, in addition to vlan ring 10, configured on the switches of ring10
vlan 50 and vlan 60, in addition to vlan ring 11, configured on the switches of ring11

Now there is the problem that there is no communication from a ring 10 and ring11.
What could be the problem?
Thank you very much.