8 CLUSTER node environment

Having issues with one CLUSTER node abending with 'CLUSTER: Node castout, fatal SAN device alert'. Running version 6.90.04 (6.90d) of QL2X00.HAM not 6.90.13 (6.90m) supplied with NW65SP6. The latest driver supplied by QLogic is 6.90.15 (6.90o), would you recommend replacing the FC card or testing the latest QLogic driver. Is it safe to run a different driver on that CLUSTER node compares to the other 7 CLUSTER nodes?