don't think anyone said anything about oil. but are you sure you have the qs enabled? as asked earlier.. and by "rapid", what do you mean. You can only upshift as fast as the bike can rev to the point of needing another upshift.
Like melk man said.... Make sure the rear set is properly lubed.... I had the same issue as you and found out that when I installed my woodcrafts.... I didn't lube the parts and it was binding which didn't allow the shift rod to return to its proper position. Sprayed some silicone spray in the proper spots and never had the issue again.