[Zope] Browser Id Cookie problem

Hi All, I've a strange problem with the Browser Id en Internet Explorer 6 clients. Sometimes a client keeps getting a new browser id and as a result the sessioning doesn't work. This is resolved bij removing the cookies of the client, after that the client is keeping the same browser id again, but after a while the same problem can occur again. Has anyone had the same problem or anyone to know a solution to this problem? Greetings Ralph PS: Using Zope 2.7.3