On Debian systems since the release of Etch and on Ubuntu systems for a while, the root account may be disabled. In such case, the first reated user is generally added to sudoers. However, SWAT insists on login in with the root account and the root account Unix password. Would it be possible to offer an alternative login method for users of such setups? The same "bug" is reported in Ubuntu as well (https://bugs.launchpad.net/debian/+source/samba/+bug/5608)
There are some ways to do this, but let's bring it up on the samba-technical list rather than here for a wider audience.
swat is removed with 4.1