similar problem for me, it started about 2 days ago:

1. when i use jdownloader it says "Disconnect? waiting 4:38 mins", it doesn't even ask for chaptcha recognition

2. and when i use the browser, it asks for captcha, i put the captcha in, it counts down from 20 down to 0, after counting down, it keeps at 0 without showing the green "slow download" button!!

:outch: