Balsa 2.3.28 on Ubuntu 9.10 - My "to:" line gets deleted

[Mike Witt <mikewitt 2009 gmail com>]

I have two systems, one running Fedora 11, on which Balsa 2.3.28
works fine. The other (a new one) running Ubuntu 9.10 on which
Balsa 2.3.28 works just the same EXCEPT THAT I can't send mail
because the "To:" line I enter when I compose the message disappears
when I send it. The "to:" line also goes away when I save the message.

Can anybody tell me what I might be doing to cause this problem?
As far as I can tell :-), the balsa configurations are the same on
the two systems.

Thanks!

-Mike