info4u - if you are running ZoneAlarm, for example (it comes highly recommended by many on these forums) you will find that pprune chat will play funny bu&&ers. Sometimes it will refuse to load, sometimes it will let you in and then bin you out of chat.
If you are going to use pprune chat, either disable ZoneAlarm, get another firewall program that allows pprune chat to carry on unmolested, or avoid chat altogether