kmail does not log into POP3 account

Hi,

when trying to check mail for a POP3 account, kmail always pops up a 
notification that it can not connect to the server because the password may be 
wrong and that the server says that a SSL/TLS connection should be used.

I can't see any errors in the configuration of the account, and a test with 
Thunderbird has shown that the account indeed does work.  I am using the 
account right now with kmail, accessing it through IMAP rather than POP3.

I have created and removed the POP3 account several times and thougourly 
verfied and tried all the settings available for POP3 accounts.  Just kmail 
always refuses into log into the account.

What could be the problem?  Is is a known bug?  Is there a way to make kmail 
show the communation between the server and kmail?