Sev, I think the other Aspies you know at your school might be the type that is very confident in their attempts to socialise, but still make many blunders, as oppose to those who meekly shy and make less obvious blunders. Are they extroverted around other NTs as well, or just in your group, or just in groups of people with similar interests to them, the sort of thing Arashi222 was talking about? I think it all depends on the context. I too can seem like an extrovert if I'm talking about my obsessive interests (books, movies and linguistics) with only one other person - it's amazing how much simpler that is, when you don't have to fight so much for the floor - or in a nice, slow, civil conversation where people take turns.
I certainly know what it's like to be different even around your own kind. I've never met an Aspie who, like myself, doesn't watch Doctor Who and lacks a lot of common sense, and I've met quite a few Aspies. I'm definitely usually an introvert, though. If a thought or emotion enters my brain, rarely do I have the instinct to announce it or make it obvious to everyone around me, unless I'm very comfortable with the group I'm in and have been asked to explain a confusing gesture or facial expression I made.
But, yes, when I started socialising with Aspies I was rather disappointed that they were not more like me, and that there were still a few difficulties I had that no one else seemed to have. However, a lot of the time, they might still be able to relate to your introverted tendencies but just find it difficult to show it.
Also, I recently took an IQ test as evidence for an application to type my end-of-high-school exams, and found out that most Aspies score terribly at verbal reasoning but brilliantly on perceptual reasoning (visual thinking) however, for me it was the other way round. It doesn't bother me though, in that respect I love being the odd one out.
