404 errors on our forum

[Young Mister Grace]

 HI Nabble.

Having problems with our forum all day.

Front page opens, but without CSS styling: http://one-for-the-dads.979225.n3.nabble.com/

But every discussion or folder link leads to a 404 error page:
http://one-for-the-dads.979225.n3.nabble.com/New-Chat-thread-21-tp4186427.html

Can you help?