As we have always done using samba 2.2.x, we are mounting a share from a windows 2000 box into the linux system and then export it using samba. This had worked without a problem until we use SuSE 9.1 Pro and therefore Samba 3.0.4. It initially works, but is very unstable. After a few hours the mounted directory is no longer accesible (doing an ls on the directory gives an I/O-Error, doing umount gives a device is busy, doing an fuser -m on the directory gives an I/O Error too. All i can do then is reboot the machine....
this is not a samba issue, smbfs is known to be very broken and not part of samba. btw - better use CIFS, it's more stable in the meantime and actively developed, so if you have problems with cifs, there is a chance that bugs are being fixed ;-)
We have now switched to cifs and did not have any problems since. Thanks for the fast reply!