Perhaps you might try setting the maximum arc output in Bobcad to 180 degrees or even 90 degrees. This will produce more endpoints whenever a full circle is required, but it also removes the ambiguity.
Using R may have restrictions as well. From what I've read, +R values are good up to 180 degrees of arc after which the sign must be inverted. I would simply stick with I and J arc centers just because of problems with handling R correctly.