Problems with a new 2008 Failover Cluster

I recently set up my first Window 2008 failover cluster and it's not working
properly. I've set up quite a few Windows 2003 clusters with no issues but
this 2008 cluster is giving me problems - I hope someone can help.

I have two identical HP ProLiant DL380 G3 servers with identical NIC's.
Shared storage is an EqualLogic iSCSI SAN and I've set up two SAN volumes
that are seen by both nodes. My network setup as seen by the cluster is:
Production Network (allow cluster to use and clients to connect), IPSan (Do
not allow cluster to use), and Heartbeat Network (allow cluster to use). The
Heartbeat NIC's are set up with 10.10.10.x addresses and are connected
together with a crossover cable. Before and after creating the cluster all
of the validation tests passed successfully. The only cluster service
currently set up is DTC.

When Node 1 is the host server I can ping the cluster name, the cluster IP,
and the DTC IP. When I fail over to Node 2 I can still ping the DTC IP but I
can no longer ping the cluster name or the cluster IP. Any thoughts on
what's going on here? I would think that if I had something misconfigured I
would fail some of the validation tests.

Thanks in advance.