Specifically I am trying to launch firestarter as a non-root user on Gentoo. The non-root user that is invoking firestarter is allowed do so w/o password thanks to a line in the sudoers file.

The problem is with the process running in root connecting to the display:

$ sudo firestarter
(firestarter:31698): Gtk-WARNING **: cannot open display:

Have tried:

$ xhost +local:root

without success.

The curious fact is that the following will work:

$ su
$ firestarter

So whats the deal with the error?

Thanks.

Perhaps try specifying which display to open firestarter on; for example:
$ sudo firestarter 0:1
$ sudo firestarter :0.1
$ sudo firestarter :0.0

or something like this, I can't quite remember the syntax, and your display number *may* vary, but it works in other similar situations, to get the application to open on one specific display. I don't know enough about the whole thing to guess why it works with the other commands, except that I think X runs as root, so unless you either ARE root, or specify root's display with enough priveleges, it will default to using another display. .

Off topic - but what is the line that allows you to do this? I tried messing with visudo to allow myself to use wlanassistant without using the PW, but enentually gave up, I'd like to know the solution! Thanks.

Simply

Thanks but they didnt work. It may well be on the right track, but its a very difficult google query to construct ...

Ah ha ... Adding:
to sudoers (allows user to export variables) appears to work.