[fetchmail]mailbox selection failed and lock busy on server error

Hi all,

client : Mandrake Linux 7.1 kernel 2.2.18, fetchmail compiled with 
./configure; make; make install

server 1 : WU IMAP4rev1 2001.292
server 2 : CommuniGate Pro IMAP Server 3.3.2

communication with servers through a ssh tunnel.

I'm not really sure when it began, but when I now get 

fetchmail: mailbox selection failed
fetchmail: lock busy on server error while fetching from nnmail

when I do "fetchmail -c serverN" and this for both servers. However, I 
can grab the mail fine using "fetchmail serverN".

I get the error with 5.7.[012] but I'm not sure about previous versions 
(not on disk anymore).

Using -v :

[cbueche(_at_)big cbueche]$ fetchmail -v wcmail

fetchmail: 5.7.2 querying wcmail (protocol IMAP) at Wed 07 Mar 2001 
10:11:06 AM MET
fetchmail: IMAP< * OK CommuniGate Pro IMAP Server 3.3.2 at 
ip-worldcom.ch ready
fetchmail: IMAP> A0001 CAPABILITY
fetchmail: IMAP< * CAPABILITY IMAP4 IMAP4REV1 ACL NAMESPACE UIDPLUS 
IDLE LITERAL+ QUOTA STARTTLS  AUTH=LOGIN AUTH=PLAIN AUTH=CRAM-MD5 
AUTH=DIGEST-MD5
fetchmail: IMAP< A0001 OK completed
fetchmail: IMAP> A0002 AUTHENTICATE CRAM-MD5
fetchmail: IMAP< + PDI3MjAuOTgzOTU2MTQ2QGlwLXdvcmxkY29tLmNoPg==
fetchmail: IMAP> Y2J1ZWNoZSA1ZjI1ZTNlOTI1YTQ3YWQyYTBhMjY4NTc0ZDdmOTkzNg=
=
fetchmail: IMAP< A0002 OK completed
fetchmail: IMAP> A0003 SELECT "INBOX"
fetchmail: IMAP< * FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
fetchmail: IMAP< * OK [PERMANENTFLAGS (\Answered \Flagged \Deleted 
\Seen \Draft)] limited
fetchmail: IMAP< * 0 EXISTS
fetchmail: IMAP< * 0 RECENT
fetchmail: IMAP< * OK [UIDVALIDITY 232252685] UIDs valid
fetchmail: IMAP< A0003 OK [READ-WRITE] SELECT completed
fetchmail: No mail for __username__ at wcmail
fetchmail: IMAP> A0004 LOGOUT
fetchmail: IMAP< * BYE CommuniGate Pro IMAP closing connection
fetchmail: IMAP< A0004 OK completed
fetchmail: normal termination, status 1

[cbueche(_at_)big cbueche]$ fetchmail -c -v wcmail

fetchmail: 5.7.2 querying wcmail (protocol IMAP) at Wed 07 Mar 2001 
10:11:18 AM MET
fetchmail: IMAP< * OK CommuniGate Pro IMAP Server 3.3.2 at 
ip-worldcom.ch ready
fetchmail: IMAP> A0001 CAPABILITY
fetchmail: IMAP< * CAPABILITY IMAP4 IMAP4REV1 ACL NAMESPACE UIDPLUS 
IDLE LITERAL+ QUOTA STARTTLS  AUTH=LOGIN AUTH=PLAIN AUTH=CRAM-MD5 
AUTH=DIGEST-MD5
fetchmail: IMAP< A0001 OK completed
fetchmail: IMAP> A0002 AUTHENTICATE CRAM-MD5
fetchmail: IMAP< + PDI3MjEuOTgzOTU2MTU4QGlwLXdvcmxkY29tLmNoPg==
fetchmail: IMAP> Y2J1ZWNoZSBkYjdmNDBkZGIzNDIxMDUyMDc1MmMwYzk2NDVkYjkwZA=
=
fetchmail: IMAP< A0002 OK completed
fetchmail: IMAP> A0003 EXAMINE "INBOX"
fetchmail: IMAP< * FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
fetchmail: IMAP< * OK [PERMANENTFLAGS (\Answered \Flagged \Deleted 
\Seen \Draft)] limited
fetchmail: IMAP< * 0 EXISTS
fetchmail: IMAP< * 0 RECENT
fetchmail: IMAP< * OK [UIDVALIDITY 232252685] UIDs valid
fetchmail: IMAP< A0003 OK [READ-ONLY] EXAMINE completed
fetchmail: mailbox selection failed
fetchmail: IMAP> A0004 LOGOUT
fetchmail: IMAP< * BYE CommuniGate Pro IMAP closing connection
fetchmail: IMAP< A0004 OK completed
fetchmail: lock busy on server error while fetching from wcmail
fetchmail: normal termination, status 9

Charles