The problem actually disappeared for me now. I have looked into this a little bit though, and unfortunately this does not mean that there is no problem: the cross-site tracking option probably learned that *I* have visited the bibbase domain often enough to infer that it was trustworthy (to me). For people who visit a bibbase based website (eg, mine), but not the bibbase domain directly, the problem may persist. This is harder to test, but yet a real worry.

Thanks for the response! The publication list doe load, but most of the formatting gets lost, the links and folding/unfolding capability do not work anymore, some technical banner describing how to embed a bibbase part in a website appears at the bottom (with random formatting)... 
The easiest way to diagnose the problem may be to check an example on my website (www.emmanuel.chemla.free.fr), toggling on and off the option in Safari and reloading the page shows the differences.