SAN volumes locked on Macs after SNFS MDC upgrade

After upgrading from SNFS 3.5.2 to 4.2.2, all Mac clients mounts but read only with a lock on the drive icon. Linux however has full read/write.

Mac clients are Snow Leopard and Mt. Lion.

Solution (thanks to Ivan):

Scenario 3 in this article:
http://support.apple.com/kb/TS2742

sudo chflags -R nouchg /Volumes/VolumeName