Hey folks... I'm trying to upgrade a 3GS on 4.1 (BB 05.14.02) to 4.2.1 *and no further*. Basically, I'm trying to use as low of a version of iOS to keep the device as lean as possible; I figure once I get newer and newer firmware, the hardware will be less and less able to support it without lag. I need 4.2+ only to run the app for my Nest thermostat. I've downloaded the IPSW (8C148), backed the device up, hit shift-Update and pointed to the IPSW I've downloaded, but always get the same message: "The iPhone "(name)" could not be updated. An unknown error occurred (3194)." I have the feeling I'm missing something simple. Can someone point it out to me, or tell me how else I'm doing it wrong? TIA!