Its not a problem at all.. can confirm this with the content link. Use it some time at some sites. Kontera is still alive after some years.. they got extra investment, if i am correct, some months ago. The only thing what should be better at Kontera is that they should get some more advertisers. They have some big companies but thats not enough. I would like to see more, more better options for visitors. They pay well in some niches.
Yes, google changed its adsense policy sometime in Jan 2007 to allow adsense to be used with other ads from other advertisers. Though I wouldn't say they're as good as adsense, but I like thier unobtrusive inline ads.
One of the problems with Kontera is the lack of relevant ads. There are advertisers bidding on keywords that have nothing to do with actual product of service being advertised.