Even after updating to hal 0.5.8.1-9, I still see this problem. I am getting the exactly the same error as reported by Markus Huber. Has this been fixed?
Today I upgraded my etch box completely just to see if this solves this problem and it did. The USB drive mounts and unmounts nicely. So may be to solve this issue not only hal but other packages might have to be updated as well. raju