I thought it was firmware or BIOS at first since the one loaded on the server is dated 2009. I did some research before updating and saw many issues others are having such as the following thread -
It seems that a lot of the servers are rebadged Quanta CS24-TY and the Dell firmware causes a lot of problems since they are different machines but with the same name/model number. I'll try to 5.1 to 5.5 update route, if it doesn't go well then I'll just settle with 5.1 for now.
What do you have running on your setup? I'm guessing you have the same servers since you answered my post.