4 KudoZ points awarded for this answer. Comment: "I have to confess to having done something sneaky (though, I guess, sneakier things have been done before). The sentence I enquired about is in fact from a bilingual (French and English) abstract for the article (in French) I am reading. The supposed English equivalent reads as follows: “This unexplained homology, brought to light through a structural analysis, is used as an example of the temporarily or definitively unsolvable difficulties that still crop up in comparative mythology”. Reading these two texts side by side I wondered how the translator had got “still crop up in” from “continue de se heurter (a)” and whether that could be justified. (Never mind how they got “unexplained homology” from “rencontre inexpliquee”!). All I found (for “se heurter” when I scurried to the dictionary were things like “collide” and “clash”). The combined response of all has been very edifying. All of the answers have merit but I liked that of Ms. Jane Lamb Ruiz best because it reads well and does not depart from the intended sense of the original – unlike “still crop up in” which occludes the sense of agency of the implied researchers. “Still run into” also would have been a good choice – but I had to choose just one. I am very grateful for these responses and, indeed for everything I have learned about translation in a very short period at Proz.com."