I have two 9800s, both bought this year as 'new', unopened items - they work just fine.

I've just amended my xcf file to include the scroll wheel as track forwards/back on the CD, and am baffled to find that it works on one 9800 but not the other. All other functionality is fine.

I had a 9400 many years ago, and that wouldn't accept programming for the scroll wheel, so wonder if this is something that might depend on the date of manufacture. Any ideas?