Server :: Oracle CRS Rebooting Node?

I am running a 5 node 11g RAC cluster with cluster ready services. The hardware is HP BL460g6 with virtual connect modules on each chassis. The OS is RHEL5.5, 2 Qlogic 4G fibre cards, 2 Broadcom NICs bonded, and the backend disk is all Hitachi 15k. The issue that I'm seeing is periodically each day there are spikes in I/O waits for disk writes, and sometimes that will cause a node or 2 to reboot when CRS can't communicate with the other nodes. Both nodes that have been evicted, are on the same chassis. What I've checked is, the backend storage is not seeing ANY high utilization, in fact it's running at less than 10% all the time. The network is 10G, and is not showing errors on the switch, or on the blades themselves. The redo logs have a 10M buffer cache, and are running on ASM disk. What other information would be beneficial to check? I am seeing nothing in the logs as to any errors, or waits for disk writes. I believe it's a software issue, but am lost as to how to prove it. These aren't the only nodes experiencing periodic high I/O waits, and it happens at the exact same time on all systems, whether they run ASM or are part of a cluster.