hi, all,
I meet the same problem that it prompts error for "sudoers file: syntax line 58...." when acquiring root access to my N810.
This is the procedure I did:
1. install openssh, openssh-client, openssh-server throught 'Application Manager'
2. assign password (I set 'qqqqqq' for that) to root user
3. open Xterm and run 'ssh root@localhost' and acquire root access
4. run 'passwd user' in Xterm
5. run 'echo "user ALL = PASSWD: /bin/su" >> /etc/sudoers'
6. run 'passwd -l root'

After all these steps, I logout root ssh and begin sudo and get error "sudoers file: syntax error, line 58...". When I return back to root access throught ssh, it prompts my password for root uncorrect. At this time it also prevents me from running 'Application Manager'. Lousy!!! I have no idea how to recover it. Thanks for advice.

BTW, anyone here tries to install 'maemo-pc-connectivity' on N8x0 following maemo.org instruction? I want to install it in ssh's root privilege but fails. Then I decide to add sudo privilegd for normal user and result to this issue.