Insecure connection and stored passwords disappear I am troubleshooting my dad's computer and I am confused about what's going on, sorry if the symptoms are a little bit all over the place. 

I am connecting the computer with a wifi that all other computers seem to have no problem with.

On his computer I have the following trouble and the following symptoms:


Webbrowser: trying to open "https://google.de" claims to be an insecure connection. 
Dropbox also cannot connect because it is supposed to be an insecure connection
Mail asks for passwords that it previously remembered. They also still seem to be stored in keychain.
Every now and then the computer seems to also forget the wifi password and I have to manually enter it.
A weird dialog pops up rapidly and then quickly closes by itself. I had to try a few times by taking a screenshot to capture what it says. It is saying (roughly translated from German): "Do you want 'nmblookup' to accept incoming connections"


The Mac is running OS Version 10.6.8
Ok, so it seem like that by going into "Disk Utility" and doing the sequence "Verify Disk Permissions"->"Repair Disk Permission" did the trick.