2nd Body Language Acquisition

I have about 2 years in the field now, not all at once, but close enough.  Given my particular field site (an ESL game company), my time in language classes filled mostly with college students or recent grads, and the overall topic of video games, most of the people I associate with on a day to basis are quite Westernized. Many of them have studied abroad and they all speak English to varying levels. This has perhaps slowed my Chinese language learning, but it has not completely stalled it, and I have been getting by alright… until recently.
I have, just recently, had several opportunities to break away from my usual research circle and spend time with some Taiwanese who don’t have anything to do with video games (not to say that I don’t ask them their opinions on this anyway, but let’s not digress just yet) and who are not nearly as Americanized as many of my younger friends/informants are. Suddenly, after 2 years, I am realizing that I am even less confident in my ability to read body language here than I am in speaking Chinese! I didn’t notice this before, because it wasn’t a problem before. 
Now, I don’t actually know for sure why it wasn’t a problem before, but it is now.  Is it a cultural factor? Is the generation of people around or younger than 30 so enculturated by Hollywood and Silicon Valley that I can understand their body language without translation? Or is this a generational problem such that I would be uncertain regardless of cultural background?  These seem to be the 2 most likely explanations to me, but of course there is a 3rd option.  Perhaps the problem is internal. Maybe I have gone so far out of my comfort zone (what I have spent years studying) that my brain is putting up a mental block out of stress and not allowing me to read signals that I would otherwise understand.

One thing is certain to me.  Body language is not taught in any foreign language class that I have heard of, and perhaps it can’t be.  I have already tried describing various situations to some Taiwanese friends, but they are in disagreement.  Of course this would seem to only rule out the possibility of my problem being cultural (if that).  It still doesn’t solve the problem.  I don’t feel like I can ask people directly about this either, because something a person would communicate with body language is probably something they either don’t want to say or would have trouble saying verbally because they are not accustomed to needing to. 

I haven’t yet decided how to tackle this problem.  I have mulled it over and come up with ideas, but no one plan strikes me as so good that it is the obvious choice. This whole dilemma also has my thinking beyond my immediate hurdle. 
Can cross cultural body language be taught? I mean, really taught to the point that one could become “fluent” in it?  I know business language textbooks have small “cultural” sections in them, but everyone I have seen covers the surface of relationships at best.  I have never seen one that digs to the heart of this question. Or is this something that foreign language textbook authors just keep forgetting to cover?