Online backup errors

I’m not technical but I do appreciate the importance of backups. I installed Online backup and it’s been running in the background but it keeps throwing up errors. The forum gives a technical explanation, but doesn’t tell me if the backups are working fully and whether I need a different approach.

I want to upgrade to WordPress 3.5.1 but I’m very nervous about doing so without a backup.

The errors follow, can you assist please?

26th Jan 2013 12.00.37 PM Warning Table ‘wp_visitor_maps_ge’ has no PRIMARY or UNIQUE key! Backup of this table may be inconsistent; some rows could get missed. See FAQ for more information.
26th Jan 2013 12.00.37 PM Warning Table ‘wp_gdsr_votes_trend’ has no PRIMARY or UNIQUE key! Backup of this table may be inconsistent; some rows could get missed. See FAQ for more information.
26th Jan 2013 12.00.37 PM Warning Table ‘wp_gdsr_multis_values’ has no PRIMARY or UNIQUE key! Backup of this table may be inconsistent; some rows could get missed. See FAQ for more information.