It appears that about 10% of the time, I see no advertisement at the top (below the "search" field) and instead, I only see "Error". Is there a bug or something (a 404) that's causing certain ads to not appear. I just saw this for the 15th time today, most recently only 3 minutes ago.
Well, it seems to have gone now. It was happening a lot on that day and it gradually decreased. It was probably that the server was down. I'll let you know if I see it again. It's nothing more than a white background with "Error" in the top left corner in the 720x90 banner ad.
I got it to happen again finally and this time, I got a screenshot of it. It's very rare, but it's still happening:
Notice the white area with "Error" in it. I looked at the HTML source of the page, searching for that string, "error", but nothing seems to hint toward an image (from the "img" tag) so I can't tell what the source is supposed to be.
For reference, I'm using Firefox 7.0.1 under Windows XP Pro SP3. I have zero add-ons and extensions beyond nothing more than Flash.