I've encountered the bug:
Very big whole numbers don't appear to be WHOLE
For example 1010100005 (even if you don't calculate it and assign to variable directly as number) is showing by C2 as 1010100004,99999
Look at the given example: BigNumbersBug.capx and try to increment and decrement test number.
I suppose this bug is located in the C2 real/integer types' conversion method.