Prohibited sign on startup - disk utility problems

Hi,

my grilfriends MacBook Air running Lion now shows a prohibited sign after start up. I got into the disk utility using cmd+r at a new start up. The first thing I noticed is that I can't check the Macintosh HD partition, only the APPLE SSD. Doing that, I get some errors (marked red in the log). I see something like this:

Unable to bootstrap transaction group 1092: invalid field value

Unable to bootstrap transaction group 1089: invalid field value

Unable to bootstrap transaction group 1086: invalid field value

Unable to bootstrap transaction group 1084: invalid field value

No valid commit checkpoint found

The volume CF.... was found corrupt and needs to be repaired

Within the partition table errors occured that could prevent the computer from startup (I translated this since it is shown in german)

Has anybody an idea on what I could try to repair it? Pressing "repair volume" ends with an error message. I would be glad if I could at least save the data so that I can make a fresh installation.

Cheers

Phil