I seem to get this too at high revs. Seems easy to miss a gearchange & get a loud 'crunch'. Feels as if the gearlever rifles thru the gate really fast- makes you try to change quick. I find you have to take more time- make sure the gear is in correctly. Easy to rush a change when you're accelerating hard
Not sure whether it's a common fault or not tho.
I had the gearbox oil changed as soon as I got my car (nov '08), Honda reccommend changing it every 2 yrs, although I will change mine every time I change the engine oil. 1st to 2nd is a problem change on the DC5's apparently, especially when cold.
Hope this helps!
Mark.