F3G - Good question. Not a clue. I've never had co-channel interference on 128.95, and I don't know of anywhere else using it anywhere near here. (I'm sure it's used somewhere, but don't have one of those giant frequency lists to check.)
I would guess/surmise that somewhere there's a master plan to redistribute frequencies so that the risks of co-channel interference are minimised.
I remember when Lille moved to 120.275 and a certain Southern England airfield had to change its A/G frequency rapidly.
The bit that worried me more about this one was that it didn't get communicated via any of the channels I watch (OK, it was in AIRAC 7/2003, but I'm not in the habit of downloading 24MB of those every month). Hence the posting here, which seems to have been the first a few Essex lads heard of it.