The slang expression "кидать понты" means kinda "to try to look "bigger" than he/she actually is". An example of "pure понт": a guy, who actually can't afford BMW M5, buys a pre-owned BMW 520 and then attaches M-style spoilers and the M5 label to it, pretending that he drives much more expensive car.
Generally speaking, any annoying demonstration of richness, higher social rank, etc. can be called "понты".
Personally, I would interpret the phrase in question as "Once again, he can't do it without showing off!" said in a rather rude way. For me, "понт" can be used not only when we talk about someone who tries to look in a more prosperous condition than he really is, but as a mere slang word for "the act of showing off" (I'm not a pro in slang, though )
You can also check out the translation of that word in Abbyy Lingvo (http://lingvo.yandex.ru/en?text=%D0%BF%D0%BE%D0%BD%D1%82&lang=en)
кидать понты actually means "to show off" and the phrase you've been trying to translate in English sounds kind of like "can't not to show off" or "he just has to show off". That's the simplest you could put it.