I have a question.

This is the first time I've heard about this. Personally, I've never seen an indication that he is. I know alot of people don't like Jar Jar because he's clumsy and weird but I've always got a kick out of him. He has a big heart, just not a big brain.

Some foreigners may find that he's portrayed like they are. You know, with the accent. Like if you aren't from the US, you aren't smart.

That's my guess. He kind of makes fun of Asians, though not any Asian group specifically.