I have noticed in the past that I have run up against the same problem.
Some where along the line, one of the programs used in drawing, or creating G-cod (Lazy-Cam), has rounded down a very small number, say ".0002" to ".000". What I did for a quick fix was to just make the zero radius the smallest number acceptable by my CNC program.
For me it wasn't a serious problem, but I would check to see the settings in all your programs, to make sure they all have a decimal place setting of 4 (".0000") to allow for small fractional numbers without rounding down.
Hope it helps a little