This has been a bug since openSUSE 10.3, see this bug report: https://bugzilla.novell.com/show_bug.cgi?id=456469
As you can see, it’s supposed to be fixed. I’ve checked, smbfs isn’t running in Yast’s runlevel editor and (for me at least) it won’t start.
Looks to me like you need to file a bug report similar to the linked bug report, but for 11.2.
I just spent some time checking it out. If you have the runlevels (yast → runlevels → expert mode) set to 3 and 5 and then “enable” it will assume the status of set and running. When next you reboot it will work and assume the correct runlevel status, provided you have a valid cifs mount description in fstab.
You can test your cifs mounts before rebooting with the command: sudo mount -a
Make sure to have the option _netdev in the options list