This happened to me too, from time to time, not very often though. I still have no clue about such random result. However, what I found to be somehow useful is to spray the accelerator from, at least, 25-30-40 cm, with the lathe turning at the same speed as for applying CA (around 200 rpm), and in short shots, 1 or 2 max. Don't worry about the distance, the particles will reach the pen anyway and you should not necessary cover the entire surface, it works in chain reaction.
When I had such incidents I sanded the pen with 120/180 grit until I got an uniform smooth surface and then start the process again. Trial and error is the way for self learning and it's probably the best, as you'll never make the same mistakes again (instead, you'll make another 1000 new ones!). Good luck!
