Let's see a example.
If you have a pad with round conens(radius_rect_95x23_radius_6)like below
S P 0
OB -0.0475 0.0055 I
OC -0.0415 0.0115 -0.0415 0.0055 Y
OS 0.0415 0.0115
OC 0.0475 0.0055 0.0415 0.0055 Y
OS 0.0475 -0.0055
OC 0.0415 -0.0115 0.0415 -0.0055 Y
OS -0.0415 -0.0115
OC -0.0475 -0.0055 -0.0415 -0.0055 Y
OS -0.0475 0.0055
The trouble is coming becasue CAMCAD can't properly interprets arc objec at all.
Here is the CAMCAD display snapshot:
Because CAMCAD's poor interptation to arc objects, more issues will raise if you try to use CAMCAD in assembly environment where you hope to extract stencil data etc.
This issue, which I believe you have identified in ODB++ read, has been fixed in the upcoming Update 3 for CAMCAD. There was some incorrect arc handling but it was fixed in this update,
Much thanks for updating me!