[Evolution] View panel of messages is gone??

[Alexandre Aractingi <aaractingi libertysurf fr>]

Hi all,
I use Evo 1.0.2 (I never had any problem with it) and suddenly today the
view panel of messages in my IMAP mailbox is gone. I can't make it
reappear, although I select the option in the view menu.
For testing's sake, I also disabled the panel view of messages on
another mailbox (POP3, that was still working) and now I am unable to
bring it back on either one of them!
Is it a known problem?
Thanks for any help!
Alex