Hi,

I gave the `kill-line' symbol a property of 'kill for 'delete-selection.

After the region is killed, "delsel.el" attempts to deactivate the region, but 
of course in transient-mark-mode buffer modification deactivates the region 
automatically, leading to an error.  I've got a patch (see atached), I don't 
know if it's too simplistic, though.  I'm no lisp expert.

--
Le