I have to go back in time to see if it was "always" broke (take the phone back to 2.0 somehow) but what I discovered that may, upon further investigation, be incidental to 2.0.1 is that NSNumberFormatter seems to take issue with negative numbers if the region is set to India, and seems to have the problem only on the phone -- the simulator is fine. Specifically:
NSString *newNumberString = [numberFormatter stringFromNumber:[NSNumber numberWithDouble:-1234.56]]; crashes to asm icu: DecimalFormat:expandAffix
It works fine for en_US locale and seems to be fine for France French. Works fine with the simulator set to India (Konkani). I haven't been sufficiently retentive in testing other locales as yet.
numberFormatter is set to currencyStyle with maximumFractionDigits at 6.
Still investigating. NSNumberFormatter has been a headache for me...