Backups are possible yes, however a couple of things to keep in mind.
#1: They're paid upgrades. You can order a backup from the "upgrade" link @ the forum home page (
SimpleForums in this case). Enter the forum name, select "backup access", then click submit. The rest should be done manually, and you should receive access to the backup area in your admin control panel.
#2: There is no guarantee that it will work. Unless you're familliar with modifying and installing php and sql products, you may not be able to get it to work properly. Because of the source code modifications made by the multiforum scripts themselves (specifically db prefixes, etc), the backup may not work on a default SMF install.