Looks like an undocumented behaviour change when mounting windows shares with the "nofail" option
Which caused me a hour or so of headache when moving to F17...
This has worked in /etc/fstab since F14 (and poss previously):
//remote-windows-server/music/Albums /mnt/Albums cifs _netdev,auto,user=xxx,pass=xxx,uid=1000,rw,nofail 0 0
It now fails (error 22) under F17 until the nofail is removed:
//remote-windows-share/music/Albums /mnt/Albums cifs _netdev,auto,user=xxx,pass=xxx,uid=1000,rw 0 0
Not really had enough time to find any adverse consequences as not having the nofail option in the line yet but the fact that it took so long to troubleshoot was a big pita