Seen this first hand - check under the Fixes and Enhancements section:
http://tinyurl.com/3aq8hwa
Controller can mishandle a medium error condition and crash a server - I would highly recommend getting this firmware if your servers have this hardware.
FYI - I think I installed this and have since had 2 crashes/locks since then, both act like the controller went dumb. Also the latest Version of Dell Openmanage will keep prompting you to upgrade since it can't figure out the higher number is the "newer" version, they may have fixed that by now.
*ugh*
I think they told use to update not only the PERC firmware, but the actuall HD firmware too - IIRC.