Problem with permission - not even allowed to open Safari

Hi

I have a mbp mid 2010 with 8gb ram running Lion 10.7.4

I have recently experienced problems with permissions, and have tried fixing it.

The original problem was that I wasn't allowed to update the SW via the update tool. This problem arose approx. 4 weeks ago. Before then it wasn't a problem. I posted this problem on this forum, and got help by reseting the permission to default by pressen command +R during boot, and via the terminal to reset the permissions. This did the trick a very short while....

Now I have new problem - I'm not not even allowed to open Safari due to lack of permission. When having disc doctor to analyse the hard drive it shows a very very long list, with issues.

I have a time machine backup on my NAS, but I don't have permission to access it - can anybody help, please

Br

Per