No Entry! Access Denied!

For the last 4 or 5 days, I have been unable to register my comments under Yahoo Sports. Everytime I try to sign in, I get the following error message:

"Sorry, Bad Request.

Your browser sent a request that this server could not understand.
Size of a request header field exceeds server limit.

Please check the URL for proper spelling and capitalization. If you're having trouble locating a destination on Yahoo!, try visiting theYahoo! home page or look through a list of Yahoo!'s online services. Also, you may find what you're looking for if you try searching below."

I've repeatedly tried, without success, to rectify this "error". I'm still able to access my Yahoo email and leave comments under all sections of Yahoo other than Sports. I don't know if this is a genuine flaw in the system, or Yahoo Sports has found a new & creative way of banning my comments. I see comments galore flowing in from other sources! I'm currently registering my comments under MSN Sports.