I know you weren't expecting either Dawn or Sherri to comment on the quality of the blade you are using - but I had questions and was trying to clarify my own issues with what you are using. And I didn't want to confuse other users, especially new users, who might be reading this and be puzzled.
You can choose to use whatever blade you want, of course, but we cannot support blades that do not come through our channels. So the blade is an unknown to us, as is the quality of the cut - as you are experiencing.
And we still need to know the size of the circle you are cutting just because we all learn as we try to figure out the issues you are having - and what could be the problem.
As an aside (not to confuse the issue), I use a 45 degree blade when cutting the card stock that you are - but then I prefer the 45 degree for most cuts and we all have our favorite cutting blade(s).
You might try one of our blades if you have them with the proper overcut and offset for them and see if there is a difference.