Error submitting form!

I was using my blog for several months now with no problems. Last week my blog at http://www.madisonhondanewsletter.com stopped allowing me to log-in. This is the error received:

Error submitting form!
Please make sure both javascript and cookies are enabled in your browser.
Use the back button to try again...

(Note: if this still doesn't help, then refreshing your cache might)

I have tried clearing the cookies, the cache, Javascript and cookies are enabled, I tried disabling and re-enabling Javascript and cookies, Google Chrome, Mozilla Firefox, Internet Explorer 7 & 8, Safari, logging-in from different locations, computers, operating systems and every other possible solution all to no avail.. I am a pretty technical person myself who is very computer literate …. the ONLY way I can post is through the WordPress application on my iPod or through a third-party software like http://www.zoundry.com … I can’t access the admin panel whatsoever and NONE of my users, authors or other admins can log-in either on their own computers.

Please help!