I believe that system restore in Vista does NOT backup user documents, pictures or music files. You should do regular backups of important files using a backup program or at least to a CD or another drive. I would try backing out the restore point and if you are lucky enough to get your files back I would back them up and then re-apply the restore point.
System Restore seems to back up and replace certain file types.
If your data has been somehow deleted, undoing the last restore might help. It might also also make things worse as almost anythihg you do on your pc involves writing to the HD, potentially overwrting any deleted files.
It may be worth trying a data recovery app. first, to see if you can locate and restore your missing files with that first.
It is better to d/l and run the recovery app. and recover files on a separate partition , if possible.
Here is a small recovery app. which runs just by right click and Run as Admin.