One ad at top of 120x600 ad unit

something new?

[fredw]

I know Adsense frequently reduces the number of ads in an ad unit, but didn't they use to center them or something?

This morning on one of my popular sites, I am frequently getting one ad only in a 4-ad 120x600 ad unit, and the single ad is placed at the top of the ad unit, leaving a lot of empty space below it.

And it's not that there aren't enough ads to display, because the ad unit has arrows and you can manually cause it to show other relevant ads.

I know "normal" users probably don't notice, but this big empty space makes it look to me like something on the page is broken. Anyone else getting this? Should I/we complain?

(Screen-shot stickied on request.)

[netmeg]

I think that might be a placement ad. Check your ad review center.