Mine's been doing that forever. Now it's doing it in 4th gear as well.
I've discovered a secret, when shifting into 3rd or 4th, hold the clutch in and before putting it in gear, just wait about a 1/10 a second then put it in gear, that works for me.
When you're running hard and smashing through the gears it's hard to remember to do that (I still grind all the time) But that moment's hesitation will prolong the synchro's for a little longer.
