locked on startup

when ever i restart my MacPro, the drobo becomes “locked”. It mounts just fine but when i go to copy something to it or play iTunes from it, the OS says “this is a locked read only volume”. The only solution i have found is to unmount the drobo, upplug it for 20-30 seconds, then plug it back in. when is mounts its fine. and will stay that way untill i restart, then i need to go through the whole thing again. this only happens with my firewire800 drobo, my USB drobo works fine.

Any ideas why this is happening or what i can do to fix it?

MacOS sometimes mounts volumes read-only if it thinks there might be corruption on that filesystem.
Have you run Disk Utility to check the Drobo volume?

You can also try Cocktail from Apple.

Here is our KB on read-only issues with Mac: