mount.nfs not working


I use a NFS mounted directory, mountable by any user. In SuSE 10.1, 10.2 this worked very well.
In OpenSUSE 10.3, there are problems… I found on this forum, there was a need to do

chmod u+s /sbin/mount.nfs

Did that, then it worked. But … After a day or so (or is it after a reboot?), I get again the error
mount.nfs: rpc.statd is not running but is required for remote locking. Either use “-o nolocks to keep local, or start statd.”

I found out that, after doing once, as superuser:

mount /mypubdir

umount /mypubdir

I magically could do now, as a normal user
$ mount /mypubdir
$ umount /mypubdir

but it doesn’t last, a day later I had the same error message back again… the same workarround still worked, but sometime later is still doesn’t work anymore again…

what’s wrong and how to remedy (permanently …)?