Font smoothing suddenly stops working over RDC

I use RDC all the time and was happy when 6.0 finally supported
ClearType for XP machines. For months I've been using a Vista laptop
to log in to an XP Pro desktop and font smoothing worked fine. Today,
no. The remote machine thinks it's using ClearType (and it is,
locally); toggling it off and on refreshes the screen. But the text
display doesn't change, it's always without smoothing. It is set to
run at 32 bit color but it comes in at 24 bit, not sure if that's
related.

I've checked every setting on both machines, deleted the rdp file,
etc. I haven't found this behavior described anywhere. I reinstalled
RDC 6.0 on the XP machine. I haven't installed anything much lately,
just a new wireless mouse on the laptop that I can't imagine has any
effect on RDC.

Saludos, Mig