virtual disk rebuild

hi all, We have a dell poweredge 2500, with two virtual disks (3 drives), in a raid 5 array configuration. The other morning, the first virtual disk all three disks power lights where flashing. In array manager it says that the virtual disk is rebuilding. In the events, it looks like it had tried to rebuild several times, and failed, before actually starting the rebuild process. None of the disks have the failed warning light, or are marked as failed etc in array manager (all are ready). It has been rebuilding now approx 27 hrs, and is still going. (the disks are 3 * 33 gig disks) is this normal? should i be worried (the server is the gc/dc, we only have two servers onsite) and is there anything i can/should do? The server is still in production. The only thing that happened before the problems was a windows update about 4 hours before hand thanks for your help Paul