what this problem in avast?

i am chinese,sorry for my english
what this problem in avast
after i install avast,it reboot,everything is ok
but sometimes i reboot,it will become like this
http://aycu05.webshots.com/image/36124/2000886193222883872_rs.jpg
it stops online protection,i don’t know why,
it is useless to start it in tray icon,it just stop
please tell me why and hoe to solve this problem

Thanks!

Did you read this page of FAQ ?

English:
http://www.avast.com/eng/faq-red-circle.html
Chinese:
http://www.avast.com/cns/faq-red-circle.html
http://www.avast.com/cnt/faq-red-circle.html