still grinding

Well i got a reco'd gearbox fitted about 1300kms ago. new clutch & a lightened flywheel. I find if i shift rather quick into 2nd gear, itll grind a little, but this only happens while turning or coming out of, a corner. If i quick shift off say traffic lights, itll go in fine without a grind. I had this same problem previously with my old box, where i would be in 2nd, decel, accel mid turn & it would slip out, however, if i did the same thing in a straight line it wouldnt bother it.

I cant think what would be causing this, i always make sure the clutch is fully engaged before i shift, its just really percullier that it only does it mid turn or coming out of a turn/corner. Anyone have an explanation?!

check ur transmission fluid level?

also, why do you change gears thru a corner? not really advisable.

not really thru a corner, but JUST coming out of one really....

Check for any leaks in your hydraulic system? Clutch master/slave ?
Or length of clutch cable (if cable operated).

If a problem if evident with one box to another, the problem is not in the box.
Either that or its human error. ie. Your driving style.