Let the hive mind of Engadget get that for you.
"I own an iPhone 3G and I'm looking for a decent speaker / alarm clock for it. I am going to listen music in a mid-sized room, so I want nice quality speakers with solid bass. I also want to use it as an alarm clock, so it would be great if there is such a feature. The price can be low-mid to mid-high range. I was looking at the Klipsch iGroove SXT; it's powerful, slick and the reviews are good, but it doesn't have an alarm clock feature. It's no deal breaker if I can set it up from the iPhone, but I'm not sure. Thanks!"
Yeah, this isn't going to work out on AT&T if it doesn't have 1900. As has been said, HSDPA 850 is for Telstra. This wouldn't be the first phone to be HSDPA 850/2100; the Nokia 6120 Classic is.
But yeah, I think it would be weird for Sony Ericsson to make a dualband HDSPA phone when clearly they have triband HSDPA chips. This may be a typo. When the K850 first showed up on their website it didn't have HSDPA 1900 listed.