Odd behavior on update?

I'm trying to track down a source of great slowdown on our database, and
I seem to have become stuck.

If I issue the command...

c2net=> UPDATE url SET last_hit = 971456105 WHERE memid = 1;

This is all I see of it in my -d 2 window log.

query: UPDATE url SET last_hit = 971456105 WHERE memid = 1;
ProcessQuery

The query actually never completes. Eventually getting bored, I ^C the
client, and receive the message..

c2net=> UPDATE url SET last_hit = 971456105 WHERE memid = 1;
^CCancel request sent
ERROR: Query cancel requested while waiting lock

It seems to be stuck, as no longer how long I wait for this to become
unlocked, it never wants to become free.

Suggestions on where to go from here?

Thanks,
-Dan
--
Man is a rational animal who always loses his temper when he is called
upon to act in accordance with the dictates of reason.
-- Oscar Wilde