Re: delete APN (data connection)
 

Run the second command. You will get a long list of APN entries, some of which will have paths ending in long alphanumerics like aff98e8.... Take the last segment of the path for the one you want to remove, and use it to replace "z_fMMS-APN" in the first command.

Worked like a charm for me.

Re: delete APN (data connection)
 

Why not using Gconf-Editor. It's a way more comfortable to edit and configure gconf entries.
See here ;) [Maemo 5] gconf-editor for N900 PR1.3 ready

Edit: Or, what I did was to find the proper name of the connection I want to get rid of, then opened filebox and went to
and simply deleted the folder with the name of the unwanted connection. Reboot and done!

Greetz,

..::J4ZZ::..