User has a Windows Load Balancing Server with 2 nodes setup in a server farm. We recently changed out the 5500 with a 4506 with multiple vlans. The 5500 was running vlan 1 only (spanning tree was enabled) and the setup worked. His pings from one node to another take over a minute to start responding. The WLBS mgt software also doesn't see the other node from both sides during the ICMP timeouts. Once the ICMP starts working between nodes the cluster is manageable from both nodes. User traffic is not affected, the problem only exists within the Balancing cluster and mgt software. All admin and public NICs on the WLBS are on the same vlan (so is the switch management). The ports he connects through are set to portfast but are running spanning-tree in the vlan. I don't see anything strange on the switch.
I've seen this symptom discussed while browsing MS admin websites, but don't find a solution. Any help someone can provide will be appreciated.