YTK is compatible.
Open the YTK control panel, Go to the spider web icon (security), check and see what auto-reconnect protocol version it is set too. It should be 15.
Also in the YTK control panel, Go to the top set of Gears, Click on Advanced, What Chat Captcha Server is it set too? It should be on Let Messenger Choose.
Also are you using the captcha pop-up box? Try it without that. Use the actual captcha link in the chat room window.