I assume by "VPN being cycled" you mean the VPN times out and disconnects / reconnects? If so, there's nothing you can do except make your VPN not timeout connections. mIRC isn't "reacting" to anything in this case, so much as it is being disconnected from the server. If you lose your connection to the VPN, and mIRC is being routed through the VPN, there's no way mIRC can stay connected. It's not mIRC's fault, it's how TCP connections work.