Version:            (using KDE 4.1.4)
OS:                Linux
Installed from:    Ubuntu Packages

Originally posted on launchpad:
https://bugs.launchpad.net/ubuntu/+source/kdepim/+bug/289790

Intrepid

dpkg -l | grep kdepim
ii kdepim 4:4.1.2-0ubuntu2 Personal Information Management apps from the official
ii kdepim-dev 4:4.1.2-0ubuntu2 Contains development files needed to compile kdepim ap
ii kdepim-doc 4:4.1.2-0ubuntu2 KDE Personal Information Management library documentat
ii kdepim-kresources 4:4.1.2-0ubuntu2 KDE pim resource plugins
rc kdepim-kresources-kde4 4:4.1.1a-0ubuntu2~hardy1~ppa1 KDE 4 pim resource plugins
ii kdepim-strigi-plugins 4:4.1.2-0ubuntu2 PIM file format plugins for Strigi Desktop Search
ii kdepim-wizards 4:4.1.2-0ubuntu2 KDE server configuration wizards
ii kdepimlibs-data 4:4.1.2-0ubuntu1 core shared data for KDE PIM 4 applications
ii kdepimlibs5 4:4.1.2-0ubuntu1 core libraries for KDE PIM 4 applications
ii kdepimlibs5-dev 4:4.1.2-0ubuntu1 development files for the KDE 4 PIM libraries
rc libkdepim1a 4:3.5.10-0ubuntu1~hardy1 KDE PIM library
ii libkdepim4 4:4.1.2-0ubuntu2 KDE PIM library
rc libkdepim4-kde4 4:4.1.1a-0ubuntu2~hardy1~ppa1 KDE 4 PIM library
ii libmaildir4 4:4.1.2-0ubuntu2 maildir library for kdepim
rc libmaildir4-kde4 4:4.1.1a-0ubuntu2~hardy1~ppa1 maildir library for KDE 4 kdepim

I just had to change my IMAP password on the remote server. When I did so, I closed kmail before changing the password in the system settings. When I tried opening kmail again, it always crashed with the following output on the command line:

kmail(14689) KMail::NetworkAccount::setCheckingMail: connections to server "XXX" now 0
kmail(14689) KMail::AccountManager::processNextCheck: processNextCheck, remaining 0
kmail(14689) KMail::AccountManager::processNextCheck: account "Regensburg" finished check
kmail(14689) KMail::AccountManager::processNextCheck: processNextCheck, remaining 1
kmail(14689) KMail::NetworkAccount::mailCheckCanProceed: for host "XXX" current connections= 0 and limit is 0
kmail(14689) KMail::NetworkAccount::mailCheckCanProceed: connection limit reached: false
kmail(14689) KMail::AccountManager::processNextCheck: processing next mail check for "Regensburg"
kmail(14689) KMail::NetworkAccount::setCheckingMail: check mail started - connections for host "XXX" now is 1
ASSERT: "!mSlave" in file /build/buildd/kdepim-4.1.2/kmail/imapaccountbase.cpp, line 304
*** KMail got signal 6 (Crashing)
KCrash: Application 'kmail' crashing...
sock_file=/home/cundy/.kde/socket-Bodley3/kdeinit4__0

To workaround this problem, I had to disable the networking via network manager. open up kmail, change the password in the system settings, and restore the networking again.