I have a similar problem.
Right now, I'm in the middle of conditioning the array. I could access everything without problems. I figured, while it's being slow, I'll do an update of the server. Restarted. I come back and now the array won't mount. I haven't done anything to delete the array (and the RAID Admin, when I click on "Arrays & Drives", shows that I'm still "conditioning the array" and gives the % done).
Shouldn't the array still be mounted? The manual says the array should still be accessable even though you're doing conditioning, validation, or rebuilding...