Windows 7 - No System Restore Points

I get this message when trying to do a system resore "No restore points have been created on your computer's system drive. To create system restore point open System Protection.
I have checked that system protection is turned on and the option selected is "Restore system settings and previous versions of files"
I have also set the maximum Usage to 30GB. I have tried to create a couple of restore point and it goes through the motions OK but on checking find that none have been created! Any ideas please?

I have AVG 2012 fully updated and have run a full scan also have the latest Malwarebytes installed and ran a scan with that.

See the tutorial and make it sure that system protection is turned on ..

System Protection - Turn On or Off

And then make a restore point manually ..

System Restore Point - Create

If any time in the future you start creating images for backup and restore then again turn off the System Restore utility. In fact the time to start creating images is now. You can learn a lot about imaging at Image your system with free Macrium and take the plunge.

I thought my post demonstrated that I have already done this?
I have created 2 or three restore points but when I go to system restore there aren't any there.

By any chance do you have dual boot system with xp as secondary OS? If so win xp is not aware of shadow copy used by Windows 7 restore and will erase all back up files on Win 7 system disc. Don't ask me why MS in their infinite wisdom is using shadow copy for restore files, which is not compatible with XP and why XP was never updated to at least to leave shadow files alone, in one of gazilions of security updates.
If your Windows 7 system disc is never exposed to Win XP, then I have no clue why would you have problems, it works for everybody else?

No but I do have Ubuntu installed as an option on boot up. Do you think it could be that?