I purchased the Line 6 Mobile Keys 25 to use with Garage Band and other DAWs on my iPad - the product is spec'ed as compatible with iPhone 3GS and 4 which I both have running iOS 6.0.1 as well as iPad which I have still at 6.0.
Product is recognized and works on the iPad.
It is not recognized and doesn't work on either of my two iPhones even though product compatibility says it is, and the page (Apple Online Store and Line6.com) indicates it can directly connect using the supplied 30 pin connector "with no external adapters required".
I use any of my iOS devices at any given point in time for creating music and bought this keyboard based on specs on Apple's online store and Line 6's site - there doesn't seem to be much information out there so either i have a defective keyboard (doubtful since it works with the iPad), or not compatible with 6.0.1 (running on my iPhones), or it is drawing too much power - also runs counter with the specs.
I get a dialog from iOS after a few seconds after plugging into either of my iPhones "Accessory not Supported", and none of my DAW/MIDI apps shows it as a connected device.
Additionally the Octave up/down buttons on the keyboard which light up when you change octaves up or down from the home octave on the keyboard don't light up when connected to either the iPhone 3GS or the iPhone 4.