etch upgrade: console garbled after running X

[David Zelinsky <dzpost@dedekind.net>]

I just upgraded to etch (with xorg) from sarge (with xfree86).
Had some problems with xserver-xorg not being installed, but finally
got X running again.  It seems to work fine, but when I try to switch
to a virtual terminal, I just see what appears to be a garbled and
magnified version of the X display.  It's the same no matter which VT
I try.

I know the VT is responding to the keyboard, because I can log in and
do stuff, which I can detect from the X session.  I just can't see
what I'm typing.  Switching back to the X session with Ctl-Alt-F7 also
works.

Can someone tell me how to fix this?  
Thanks.

-David