I found the problem - 5 drive array only had 4 functioning drives and has been degraded. Swapping in a new drive doesn't fix the problem, so there must be another hardware issue somewhere. The 9550 controller is obsolete so 3ware is not providing much support for it. The unit is old enough to warrant complete replacement, if I can convince the powers that be here that it's cheaper in the long run.
I'll be doing complete backup on that server today - I just hope it doesn't fail before I can replace it.
Thanks for all of your help! It is greatly appreciated! I have to say that this is the BEST forum experience I have ever had. Keep up the great work!