This shouldn’t cause your balance to be zero. I’m pretty sure this is a bter issue, my mobile app (bitcoin checker) also has issues updating price feeds from Bter, occasionally throwing errors out while other exchanges don’t do anything of the sort. Of course, that app is completely third party and has nothing to do with Nu, so I’m reasonably convinced this is a Bter issue. Again, it shouldn’t be failing to credit you, that is probably another issue.
I could be completely wrong, but this issue didn’t come about until recently and I actually haven’t changed the CNY server software in a very long time.