newbie: --edit-key problem

[Michael D. Berger]

On FC4, I execute this command:
  gpg -vv --recipient mdb00 --armour --cipher-algo blowfish --encrypt
tst.txt

and while it works, I get a warning that blowfish is not preferred.

So I ran:
   gpg --edit-key mdb00

and:
   setpref S4

I confirm that I want to do this, and then it aska for my passphrase.

However, the gui (KDE) does not accept a response.  I modified my
passphease to something trivial to get the mouse out of the picture, but
it still did not work.

Note that a similar passphrase query when decrtpting the message works
with no problem.

What am I doing wrong?  In any case, if I could get the result by
editing gpg.conf I would prefer it.

By the way, I have extensive experience studying gpg:  1.5 days ;)

Thanks for your help.
Mike.

--
Michael D. Berger
m.d.berger at ieee.org