It seems like this problem is more common than I thought. Granted, we've only heard from three people who've had issues (the OP, Woodsrider, and OneNut) but that's a significant number considering the limited number of people who've seen this thread, read it, and decided to post.
I kind of went nuts with my garage since I'd wanted one since I was about 14 and I'd been working outside on gravel most of my life. When it came to the lights, I bought 16 eight (8) foot long fixtures (4 rows of 4) with electronic ballasts, and 32 high output (HO) daylight (6,500 degrees K) T8 lamps. I got them from an electrical supply place (Tri-State?) and at the time, electronic ballasts were relatively new (at least in full size hard wired fixtures I guess). They had to be special ordered and the guy at the store tried to talk me out of getting them saying that electronic ballasts were unreliable.
It's been about 10 years now and no problems. No 60 Hz hum, no RFI, and they turn on almost instantly even when cold. Maybe there were some problems with the early ones that made the guy at the store not trust them.
It sounds like the RFI problem may be limited to mostly cheap plug-in fixtures. Still, they shouldn't be sold if they are creating that much noise. My guess is this is just below the FCC's radar (or whichever agency should be concerned with RFI from fluorescent fixtures).
Those of you who've had problems might consider shooting an email to the FCC. Couldn't hurt, and who knows -- maybe they will do something about it and prevent others from having the same troubles.
Out of curiosity, where were these noisy fixtures made? My guess would be China. It's long past time that we crack down hard on them (and large multi-national corporations) for selling us poorly made, dangerous, and often deadly products.
Makes me wonder if these fixtures are even UL listed. UL labels are among the many things the Chinese have counterfeited in the past. That's why UL went to those hologram labels but I wouldn't be surprised if the Chinese have copied those now and are slapping them on lots of electrical items.
I really hope those of you who have this problem contact the FCC (just copying some of what you've posted here would cover most of what you need to say) and maybe UL, Consumer's Union (CU, publishers of CR magazine), and the Consumer Product Safety Commission, etc.