I had the same problem tonight...12/2/10. it seems I have removed the Zedo popup.. Was it was an accident or did I find the solution?

Before I Did any of the following procedures I deleted all my cookies.

And at the top left of your browser,

Click on tools. Then click on Options Then Click on content

Then where it says Block popup windows ..make sure the box is checked next to it. Then click on exceptions and you should see Zedo.com..it should say zedo.com is blocked.  now,at the bottom you should see where to remove the zedo site. click remove. 

Next you have to drop down below popups.. And where it says Load Images Automatically, make sure the little box is checked next to it. Same thing, click on exceptions and make sure it says Zedo.com is blocked..also can remove that site by clicking remove..

I hope this works for your problem with Zedo.com..

Zedo is not listed on any of my exceptions in either place, so this does not help me.

You can try:

Install the SQLite Manager add-on to Firefox. Using SQLite add-on open the file: C:\Documents and Settings\<User name>\Application Data\Mozilla\Firefox\Profiles\<profile code>.default Where <User name> and <profile code> are system dependent.

Now perform the following query: INSERT INTO moz_hosts(host,type,permission) VALUES("", "popup", 2);

You can also change the "" for any valid URL (including the usage of '*' for pattern matching).

Zedo is a shady vendor of popup advertising. Zedo found a way to go around Firefox's popup blocker.

One of Zedo's disreputable practices: Some of Zedo's popups remain on screen for 5-10 seconds or more after the user presses the close box.

Firefox needs to enable blocking of domain names.

PS. I ask that Mr. Albright's response be deleted. He is obviously not familiar with Zedo. His answer is purely theory and assumes that people have been *enabling* zedo.com in their browsers (WTF?!? Who would do such a thing?).