Command collection for fixing a corrupt timemachine sparse bundle, extends on http://www.garth.org/archives/2011,08,27,169,fix-time-machine-sparsebundle-nas-based-backup-errors.html

fix sparsebundle

# To Monitor the whole process
tail -f /var/log/fsck_hfs.log

chflags -R nouchg /Volumes/{name of your network share}/{name of}.sparsebundle
hdiutil attach -nomount -noverify -noautofsck -readwrite /Volumes/{name of your network share/{name of}.sparsebundle
fsck_hfs -drfy -c 750 /dev/diskxs2 #-c -> amount of RAM used as "cache"
# if fsck doesn't do the magic, use DiskWarrior
hdiutil detach /dev/diskxs2

# in sparsebundle/com.apple.TimeMachine.MachineID.plist remove
<key>RecoveryBackupDeclinedDate</key>
<date>{whatever-the-date}</date>

# and change to
<key>VerificationState</key>
<integer>0</integer>