Hi,
xdg-open fails on my system without a desktop environment.
so DE is setted to nothing and the generic function is executed.
my $BROWSER variable is set to "/usr/bin/opera -newpage %s"
it fails with following error : 
[johannes@ThinkpadT40Johannes ~]$xdg-open kernel.org
 /usr/bin/xdg-open: line 370: /usr/bin/opera -newpage kernel.org: No such file or directory

a fix i found with some other in the irc chanel on freenode is to add eval to line 370 wich means the following : 

instead of:

            if [ x"$browser_with_arg" = x"$browser" ]; then "$browser" "$1";
            else $browser_with_arg;
            fi

use :
            if [ x"$browser_with_arg" = x"$browser" ]; then "$browser" "$1";
            else eval $browser_with_arg;
            fi


i hope it will be included in the next version ;)