Just to second David's advice... if you restore a backup on a different WP version than the WP version it was taken on, then restoring effectively becomes two operations in one: both a restore, *and* a version upgrade of the restored version.
To find out where the problem lies when there is a problem of this sort (i.e. whether it's in the restore, or whether it's actually in the upgrade and would have happened anyway), it's better to split it into two operations instead, i.e.:
1) Re-install WP of the same version as the backup is from. Restore onto that.
2) Then, after that, upgrade.
David