Adblock (non-Plus) appears to be blocking advertisements without reporting it even being blocked.
AB on Chrome, only AB extension enabled - no advertisements.
Chrome, no extensions - advertisements.
ETA: Actually... some advertisements load under AB. Maybe I'm just being stupid.
ETA2: No, AB is definitely blocking ads. Anything with a background image, it seems, possibly more.
<TR
class="td_headerandpost1373956846" > is blocked
<TR
class="td_headerandpost1373956921" > is not blocked
<TR
class="td_headerandpost1373956974" > blocked
<TR
class="td_headerandpost1373957100" > is not blocked (but uh... it's just a grin emoticon -- dunno if intentional. This place is crazy.)
No clue if that helps at all. With AB, ~85-90% of ads are missing. Without AB, 0% of ads are missing. (Not a huge sample size. I'm not going to refresh and stare at ads forever, y'know?!)
If it helps, this is what I see when an ad is blocked (again, no notification in AB icon):
ETA: As mentioned above, this is a block by EasyList.
bitcointalk.org##a[class^="td_headerandpost"]