My fstab in Lion contains values in this form:
LABEL=Lion none hfs rw,noauto
LABEL=TimeMachine none hfs rw,noauto
LABEL=Windows none fusefs_txantfs ro,noauto
LABEL=Untitled none ntfs ro,noauto
and it works in preventing automount of the specified disks ...
LABEL=X (where x is the name...