Thats not true. The 1g could be charged with both 5v and 12v power while the 2g only charges with 5v (aka USB) so many previous docks and radios no longer work with it. Your best bet is to check the logitech website or if you cant find anything there then give them a call to make sure.
System Requirements:
Supports iPhone and all iPod models with dock connector
Supports 1st generation through 3rd generation iPod models (and other portable music players) via 3.5 mm auxiliary input
Uses the Apple Universal Dock specification
Package Contents:
Logitech® Pure-Fi Express Plus™ speaker dock
Wireless (IR) remote control
iPod/iPhone Universal Dock adapter trays
Quick-start guide
Warranty and safety guidelines
2-year limited hardware warranty