Adsense banner offset from container

Hi,

I’m using a 728×90 adsense banner above content.

No problems with it showing up, but it appears to be offset from the container by a couple of pixels, resulting in a black “border” to top and left of the ad.

Tried various settings and custom css but nothing is working.

Screenshot:
https://www.dropbox.com/s/guyyu30aobvq60s/banner.png?dl=0

You can see the problem best in the bottom left corner.

Please advise.

Cheers.