"Edit exchange rate" has stopped working (2.2.9)

[Adam Funk]

I have a serious problem that may have coincided with upgrading from
2.2.6 to 2.2.9 in December (Ubuntu jaunty -> karmic).

When I use the "Edit exchange rate" menu item on a split, either
automatically by tabbing past the end, or by right-clicking on the
split (but in both cases, as I have been doing for years), I don't get
any errors or warnings, but when I go back and look at the transaction
in the other register (in another currency), or when I got back to
"Edit exchange rate" again, the rate and the other-currency amount
have not changed.  I cannot get the rate changes to persist now.  I
have tried all sorts of sequences of TAB and CR after clicking "OK".

Has anyone else seen this?  Any suggestions?  (I need to get this
fixed before I build up a big backlog of transactions to sort out
later.)

Thanks,
Adam