K2JJS,
It has nothing to do with there being a tone of any kind, PL or CTCSS. The carrier, or received signal is what's stopping the scan when in the 'carrier' mode. One way to 'cure' that is to determine the source of that carrier/signal and eliminate it. The other way is to change the carrier scan to a 'time' scan mode. Not a very likable solution in either method, but that's about it. That carrier or signal would stop any carrier operated scan no matter what radio used, so the 'best' way of 'curing' it is to stop the carrier/signal. That's not a very likely thing to happen either. Take you pick...
The only way to eliminate the back lighting when scanning that I've been able to find is to turn the back light off. Then, reprogram the 'FM radio' button to turn the back light on when pressed. Basically a back light only on demand. The 'catch' to that is that scanning or transmitting will turn that back light off. Guess it just amounts to which inconvenience you want, huh?
I honestly doubt if a 'firmware' up-date is possible with these HT's, so even if the factory did the programming change to suit the USA users, it'd probably mean additional cost to do the up-grading to existing radios. I can't say I'm thrilled with the back lighting, but I can live with it.
- 'Doc