Bought an Alpine CDA 9847 earlier in the year and really like it...until it turned cold. If overnight temps are in the 30's or lower be prepared for non-functioning controls and perhaps other wacky occurances too. In talks with Crutchfield it sounds like Alpine is aware of the problem and might have already done something about it and that it is only effecting the 9847 model. I was advised they can send me a new HU but can't guarantee it won't suffer the same problem though. So I'll just take the faceplate indoors at night and go from there. (Daytime temps in AL are rarely in the 30's so it isn't a problem to leave it in during the day--once the car has warmed it isn't an issue anyway.)
[Placed for the betterment of CEG on the off chance someone actually does a search on Alpine CDA 9847 and cold.]