Every time I try to start a conversation on messenger plus it signs me out, no error messages appear though.  I can do anything else for instance changing my dispaly picture and i can stay online for as long as I want as long as i am not talking to anybody.  Please help it is driving me mad.

Did this happen before you install Plus?

Yes it happened with windows live messenger as well, so i tried re-installing that and when that didn't work i tried installing plus to see if that would help, which it hasn't. 

Thanks for your help, but i've worked out the problem.  For some reason zonealarm is blocking it.  I've read that other people have been having the same problem but I'm not sure why it is doing it.  I suppose i'll have to get a new internet security programme

Thank you for the info, and yes, if ZoneAlarm is causing this kind of problem for no apparent reason, switching to a different security program is probably the best thing to do.