I found that first letter in CCLabelBMFont flickers in my game. You can see it in this video: http://www.youtube.com/watch?v=hp71TP7VnwU&feature=youtu.be (sorry for the poor quality).
I use one label for coins (center) and another one for moves count (right) attached to the CCSprite:
In game code i have no any actions applied to labels. Also I do not change any properties (opacity for example) for label nodes and its childs. Except setPosition and setString of course.
Labels initialized using standard static ctor with .fnt file generated by Bitmap Font Generator tool (http://www.angelcode.com/products/bmfont/)
This bug appears only on Samsung Galaxy Ace (android 2.3.6). On all other android devices that i have and on all iOS devices and on Win32 all ok. Cocos2d-x version: 2.2.0
Any ideas? Help please!