I have noticed that some avatars are very large, some distorted, when this happens there is a line across the page and any comment is below that line.
On the bottom of some pages the adverts cover the last comments, if I hit reply and then cancel that the advert goes back to where it should be.
Over here in Australia I am seeing mostly dating services adverts, so I have to look for a more appropriate advert to click onto so as to also discourage these type of adverts from family friendly sites.
Less clicks on them they may then put them where they could be appreciated.