strange behavior in gnome-terminal - need to reset to default

[Ray Leventhal]

Hi,

I've been happily using gnome-terminal whenever a CLI was needed.  I'm
not sure how it happened, but today everytime I press the letter u, the
contents of the clipboard is pasted into the terminal.  As you can
imagine, not being able to type sudo is kind of a pain :)

I've installed konsole for the time being, but I'd prefer to leave
gnome-terminal as my default CLI.

In my trying to fix this, I did, of course, look at the keyboard
shortcuts menu under 'edit'...and sure enough, below 'Copy' to which
Shift+Ctrl+C is mapped, the letter U is mapped to 'Paste'.

So...2 questions in order of importance:

1) how do I reset this?  I've looked and googled but without any luck
(unless I'm just not seeing it, which is always possible)
and
2) any ideas on how this happened in the first place?  I'd hate to have
it happen again.

Thanks in advance,
-R
System Specs:
Jaunty, fully updated, running on an IBM R30 system