kontact and kolab

for the last few months i've had no calendar sync in kdepim (kontact (kmail)).

org.kde.pim.kolabresource: Failed to create configuration folder:  "Create 
failed, server replied: A000031 NO Mailbox already exists "
org.kde.pim.kolabresource: Failed to create configuration folder:  "Create 
failed, server replied: A000032 NO Mailbox already exists "

this is kontact version 5.8.1 on opensuse tumbleweed ("nightly builds").

the server is kolabsys, latest and greatest. "server info" shows as follows:

IMAP4REV1
LITERAL+
ID
ENABLE
ACL
RIGHTS=KXTEN
QUOTA
MAILBOX-REFERRALS
NAMESPACE
UIDPLUS
NO_ATOMIC_RENAME
UNSELECT
CHILDREN
MULTIAPPEND
BINARY
CATENATE
CONDSTORE
ESEARCH
SORT
SORT=MODSEQ
SORT=DISPLAY
SORT=UID
THREAD=ORDEREDSUBJECT
THREAD=REFERENCES
ANNOTATEMORE
ANNOTATE-EXPERIMENT-1
METADATA
LIST-EXTENDED
LIST-STATUS
LIST-MYRIGHTS
WITHIN
QRESYNC
SCAN
XLIST
XMOVE
MOVE
SPECIAL-USE
CREATE-SPECIAL-USE
URLAUTH
URLAUTH=BINARY
X-NETSCAPE
LOGINDISABLED
X-QUOTA=STORAGE
X-QUOTA=MESSAGE
X-QUOTA=X-ANNOTATION-STORAGE
X-QUOTA=X-NUM-FOLDERS
IDLE

is this a known problem? (is there a workaround?)

-- 
Vixie