Looks like Panda might be a source causing a problem. Have you tried flushing the DNS cash?
Clearing Your DNS Cache
Your DNS cache stores the locations (IP addresses) of pages you have recently viewed. If the location of the page changes before the entry in your DNS cache is updated, you will be unable to access the page.
If you are encountering a high number of HTML 404 error codes, you may need to flush your DNS cache. Once you clear your DNS cache, your computer will query nameservers for the new DNS information you require.
For more information about the HTML 404 error code, please visit the HTML 404 wikipedia article.
The methods detailed below allow you to remove old and inaccurate DNS information that may result in 404 errors.
Windows® XP, 2000, or Vista®
- Open the Start menu.
- Go to Run.
- If you do not see the Run command in Vista, search for "run" in the Search bar.
- In the Run text box, type:
- Press Enter or Return, and your cache will be flushed.
Let's see if any clues are given in the event viewer ...
download VEW by Vino Rosso http://images.malwar...om/vino/VEW.exe
and save it to your desktop
Double click it to start it Note: If running Windows Vista or Windows 7 you will need to right click the file and select Run as administrator and click Continue or Allow at the User Account Control Prompt.
Click the check boxes next to Application and System located under Select log to query on the upper left
Under Select type to list on the right click the boxes next to Error and Warning Note: If running Windows Vista or Windows 7 also click the box next to Critical (not XP).
Under Number or date of events select Number of events and type 20 in the box next to 1 to 20 and click Run
Once it finishes it will display a log file in notepad