CTRL/U deletes line on Solaris Firefox but not on Linux

I have installed the Firefox 1.0PR release on both my Linux system at
home and my Solaris Sparc system at work.  At work on the Solaris
system a CTRL/U in the address field clears the field but at home on
the Linux system (Slackware) it brings up the page source for the
current page.

I'm a died in the wool Unix/Linux user and I really expect CTRL/U to
delete the line during text entry.  Is there any way I can get it to
work on my Linux box (it works in Mozilla 1.7)?

I know CTRL/U brings up the page source when entered elsewhere but I
don't think it should do this during text entry.

-- 
Chris Green