[Evolution] Error while 'Opening folder imap://user@localhost/mailfolder

[Thomas Baumgartner]

hello everyone,

i'm getting the following error message when trying to open one of my 
mail folders:

"Error while 'Opening folder imap://user@localhost/mailfolder':
Server unexpectedly disconnected: Invalid or incomplete multibyte or 
wide character"

I've no idea how to go about solving this issue. Could somebody kindly 
give me a hint or pointers as to what might be the problem? Thanks a lot.

I would like to add that I have 14 mailfolders in this imap account, and 
only with one do I get this error message when trying to open it. 
However, I have also installed Thunderbird on this machine and with 
Thunderbird all of the mailfolders open without a problem, even the one 
that I can't access in Evolution.

My setup:
Redhat 9.0
Postfix 2:1.1.12-1
Dovecot 0.99.10-6
Evolution 1.4.5