fileroller and unrar

[toyfactory]

I am unable to extract rar files with fileroller.  I have tried
installing both unrar and unrar-nonfree but fileroller doesn't appear to
handle rar files with either of them.  The unrar command works fine in a
terminal window.  Is fileroller perhaps looking for unrar in the wrong
place?  Does it have a config file with the locations of the programs it
uses?

Cheers,

Nick