What version are you using for the iSCSI? Is it iSCSI-R3 or iSCSI Enterprise? You might want to update again or re-flash, if this is just a new problem something just recently happend and without logs to diagnose the issue we will have to start looking at a few things, like the RAID controller or memory, perform a memtest from rebooting the system and hit the ESCAPE key and run the memtest for an hr and then after try to do a RAID verify on the Array.