Backing up ISPConfig 3 with Duplicity on Debian Lenny--exclude directories?

[PermaNoob]

--exclude /proc
--exclude /sys
--exclude /mnt
--exclude /tmp

I'm using Duplicty to backup my disk with ISPConfig 3 on Debian Lenny. In the event of failure, will be restoring to a clean Debian Lenny installation, so I won't need all the Lenny directories, just the ones that are modified by my setup.

Are the above excludes correct and can I or should I add more?

thank in advance

[till]

I think that should be ok.