[blue68f100]

If id did not use the spare, power down and remove the HD (spare). Use any utility you want to do a quick format. Any format except linux/unix. The reinstall, once the unit comes up, set it as a spare and see if it will use it. This will not happen very quick. It take around 10 min for the init to happen some times. One it it is inited, it will then start the resysnc, this can take 24hrs at time.

Just out of curisity, how full is the array/drive. If more than 90% it may have a problem.

Also have you checked to see if your unit has the updated or patched MB. The sticky at the top of the threads will show you what to look for.