dirty bit is not going away

[Armineh Nazarian_1]

I have a WIN2K server Compq ML530, patched up to service pack 3 in 2000 domain.
It is configured with 5 drives in the first cage and 5 drives in the 2nd cage. I have RAID 5 in each cage. The drive sizes in cage 2 are 72GB each (We wil call this drive E).
I have diskeeper 7.0 running on the server to defrag everyday. Everything was running fine until a power outage. After the power outage the dirty bit on the E volume which contains only data is not being cleared. I have run chkdsk /r on the box and rebooted it. it clears for a day and diskeeper can run. It gets reset back to dirty after one run.
I called Diskeeper and they say I have to low level format my E volume and restore the data.
I though with this new technology we were past low level formatting. I don't even have a tool to do this safely. Can I just replace the 72 GB disks one at a time and let the RAID rebuild itself. Will that clear the dirty bit?
I would appreciate any input.
Thanks