Failover with Exchange Group on Cluster

We have an NT 4.0 SP6a cluster with Exchange 5.5 SP4 on it. It used to take around 2 minutes to move the Exchange group from one node to the other. Now it takes 45 minutes. It only has 5 users on it, the private store is around 420 MB and the public store is at 1.7 GB. Any ideas?