Just a minor but somewhat annoying bug with Kopete: everytime I log on I get informed that another user has added me to their contact list, I've already accepted this user and they're on my list. How do I stop getting repeated notifications without entirely disabling the notificaitons for new users?

You can try disabling the notifications for that specific user rather than disabling the general notifications altogether. Are there any other "weird" behaviours?

In some cases I have found, you think you have accepted the user, but you may not have. Click the Blue Flag in Kopete's status bar. You should have no service messages waiting.

Once I click authorise there are no service messages (the flag is black, its green when I'm asked to authorise) but it reappears next time. When I check under modify account > privacy (I should have mentioned its Hotmail) the user appears under authorised contacts.

I haven't noticed any other weird behaviour apart from a minor one when I migrated, most of my contacts duplicated (or was it triplicated) into a real contact and an empty metacontact. I just deleted the metacontacts.

I do not know any specifics about how Hotmail Chat works, however one of the following is the likely cause:

1) libMSN contains a bug with regards to sending the authorization confirmation to the server.
2) Some other detail in regards to the method how the MSN protocol is handled.
3) A bug in Kopete causing libMSN to not be used correctly.