PAGEIOLATCH_SH and CXPACKET

I am seeing a high % of suspended transactions on PAGEIOLATCH_SH and CXPACKET. The server is 64 bit and has 8 cpu, 12GB memory, SQL Server 2005 Standard 64 bit has 10GB.
It's attached to a SAN. The data files and tempdb (not ideal) reside on RAID 5 virutualized, the logs reside on another RAID 5 virtualized. Here's the SAN configuration:
E: (700Gb) hosted on subsystem consisting 13 x Raid5 (7+1) virtualised with the data striped across (FC 10k disk).

F: (300Gb) hosted on subsystem consisting 13 x Raid5 (5+1) virtualised with the data striped across (FC 10k disk).

G: (500Gb) hosted on subsystem consisting 2 x Raid6 (4+2) virtualised with data striped across (SATA).

Q: (500Mb) hosted on subsystem consisting 13 x Raid5 (7+1) virtualised with the data striped across (FC 10k disk).

Each of these subsystems has 2Gb cache. The SVC (virtualisation engine) has 8Gb cache.
E: Data and TempDB
F: Logs
G: nothing. use to be backups
I suspect the PAGEIOLATCH could be steming from the RAID 5.
Any thoughts?