Translation:Éva and János are talking in front of the store.
For me (as a native speaker) both forms sound completely correct. I would myself prefer the singular form, but my wife voted for the plural version :) I am not an expert of grammar, and cannot tell which version is more correct theoretically, but both are used by speakers in daily speech.
In the thread we talked about this, Vvsey added that it can actually be correct to use a plural verb in such cases. Originally this was probably a germanism, but the rules now allow it.
Basically when there are more than one singular subjects, you either use a singular verb because the nouns are singular as well, or a plural verb considering there are more subjects. It's not clear to me when it's truly possible to use a plural verb ("Az alma és a lámpa mi között vannak?" sounds very awkward), but here both "beszélget" and "beszélgetnek" are correct.
"Eva and Janos" -> "pay attention to the accents", no, we won't give you the keyboard if you're typing in English, but we will still scold you for not using them :-> At least it counted as correct. I know, it should go to "report a problem" but in this case it didn't give me an option for a free comment, and none of the options would be fitting.