have had this problem before. on the side of the drum you will notice there are "fins", these fins act as chip pushers/air pushers. after time the fins become worn, therefor reducing the amount of air and chips being pushed through the chute. if there is less mass and less air flowing, the chips dont shoot as far. my 1400 had been doing this for awhile and my local vermeer couldnt figure it out. we tried replacing the main drive belt, that didnt work. brand new blades, that didnt work. new clutch, that didnt work. new drum bearings, that didnt work. finally me and the vermeer shop boss pondered it over for 30 minutes one day and came up with the side fins. the next day he started welding and made the fins factory spec. No more putting guys in the truck to push chips.
that should do it. send it to vermeer and tell them the deal and im sure the can fix it up in no time.
best of luck