Hey Manu,

This issue isn't so much grammatical as style. However:

1) Any usage of the noun form of being, such as "human being" is always okay.
2) The gerund form at the beginning of sentences is almost certainly okay, though I haven't seen it: "Being in love isn't always like the poets say."

In general, the GMAT will shy away from ever using being as a participle form, though I have seen it in a correct answer. I don't have it on me, but in that instance, the word "being" appeared in 3 out of the 5 answer choices, and one of them did turn out to be correct. Something like:

Even though he complained of being tired all day, he was still able to go out dancing all night.

Basically, if you ever cross off a sentence just because it has the word being, you're missing some grammatical issue. However, it does tend to be a useful guessing strategy.

-t