Degraded SATA Raid1 problem

[Stefano Giusto_1]

hi there,
I encountered the following issue tht I want to share with you.
ML150 with 4 channel SATA controller.
2 160GB SATA HDDs configured in raid1
W2K3 SBS
Suddenly the system won't boot reporting system hive corruption.
W2k3 recovery console do not work
W2k professional recovery console starts. replaced system hive with one in repair folder, system boots but never reaches logon. (hung in applying network ...).
restarded recovery console and run chkdsk. it runs very slow but goes to end with no error.
At this point I open adaptec bios (raid status is optimal) and run surface analysis on disks. Both HDDs fail surface analysis!!!
I break raid and try to boot with each disk alone but both don't work.
I replace controller, disks and restore from backup and go to sleep thinking about 2 failed disk and a raid1 status optimal...

I installed a brand new ML110 with 2 new SATA HDDs in raid1 with another W2k3 SBS.
then I removed a good HDD bringing the raid to degraded state. then I plugged one of the 2 failed HDDs of the ML150 and the raid rebuilds with no problem!!! Then I run surface analysis on the previously failed HDD and reports no error!!!
I break the raid of ML110 again, insert the other failed HDD and run surface analysis. It fails. I start rebuild on the failed HDD and rebuilds!!! then I check this HDD and surface analysis goes with no error!!!
So what am I missing?
Why the controller of ML150 did not reported any problem on the two disks? and why the two disks are now running on the ML110?
Any comment/suggestion would be very appreciated