I have asked this question before and don't know if I ever got a response. so why not try again.
When using the CREATE OBJECTS FROM SHAPES... command to convert any basic object into something else (doesn't matter what), there is a conversion of any accurately drafted arc and radius information from a point on arc mode to a bezier mode. See the attached image for comparison.
This is a frustrating phenomena/bug for the many reasons noted, but most importantly for the loss in fidelity. Once an original object is converted, there is no way to restore the original arc fidelity.
I have requested a fix for this before and feel that this should be dealt with ASAP.