It really could be clarified regarding to this double issue...
I still continue having this problem.
I´ve edited the two files
[sbox-FREMANTLE_ARMEL: ~] > vi /etc/apt/sources.list
[sbox-FREMANTLE_X86: ~] > vi /etc/apt/sources.list

both with the vim commands.
i for inserting text
I pasted the link after accepting EULA and
:wq for writing and quiting saving changes

I notice one thing:
In my terminal it never appeared
[sbox-FREMANTLE_<X86/ARMEL>: ~] >
but just one of both targets. (Like [sbox-FREMANTLE_ARMEL: ~] >)

I tried to select both in sb-menu but I did not figure it out...


The funniest thing is that the error is in the first line of the file:
[sbox-FREMANTLE_X86: ~] > apt-get update
Err http://repository.maemo.org fremantle/sdk Release.gpg
Temporary failure resolving 'repository.maemo.org'
...

Did anyone have the same problem?
Cannot wait to play with maemo...

Greets