Mine doesn't do this. It does all manner of strange things on the cold start cycle, (I reckon it has 90bhp tops!) but is steady as anything balancing the throttle and clutch after this. In fact it's been slightly better since the re-map because the throttle is now more responsive.
Check nothing on the air side of the engine hasn't come loose, maybe even tweak the inlet manifold nuts. O/w it may need putting on an emissions machine to see. Of course I am waaaay out of time, you may need to put it on one of those new fangled computers to flag up the reason!