Http/1.1 internal server error

Hi, I am trying to access my ebay. Recently i have been unable to log on, it keeps coming up with "bad request invalid verb" or Http 1.1 internal server error. I am not a techie so it will have to be in plain english please!!!!
The funny thing is, sometimes it will let me into my ebay then when i want to look at another page it brings up the error OR i just can't log onto ebay at all. Can someone please help!

1. I have Trend Micro Security 2008 and this caused me to have problems gong on To Ebay.com.au.
   Had to spend a few hours with a Tech Guy from Malaysia who created a patch for this problem..Was fixed !!
   Now today i have the same problem.
   I think Ebay change their security setting every 6 months or so and Trend Micro need to keep up with them!
   Hope this helps!
   Don't feel like spending another 1/2 hour having them download information from my pC to fix!!
   May go back to Norton i think!!!
   Rissab2005
2. Recently installed Windows Live and Family Safety; thenMozilla Firefox started getting this error on Ebay pages: "Http/1.1 internal server error" or "bad request". If I would click the address bar and enter it would randomly show the page.
   
   Un-installed the Family Safety program and now, no more error.