I ran into a highly irritating potential bug with the Samsung Charge, its Bluetooth, and the GM OnStar system.
On my old phone, a Droid X, I can pair the phone with the in-car speakerphone/OnStar system to make and receive phone calls over the Charge on the in-car speakerphone. More importantly, I can do so even when I have audio running from a cable from the Droid headphone jack to the car audio input, which lets me listen to streamed audio and make/receive phone calls without having to do a thing. With the Droid, the streamed audio mutes when using the speakerphone.
With the Charge, as soon as you plug a cable into the headphone jack, the Charge's Bluetooth audio is disabled. In effect, this means you cannot hear the calling party unless you disconnect the cable from the headphone jack. It's highly irritating and effectively means I have to reach over and disconnect the audio cable whenever I need to make or receive a phone call. (The audio headphone cable does not deliver any audio either at this point because I believe GM cars mute the radio system when a phone call is in progress on the in-car speakerphone.)
Note this involves originating/answering calls on the Charge -- not using the OnStar's built-in cellphone (with the rape and pillaging per minute pricing).
Any guidance or advice? Motorola did this correctly with the Droid, Samsung certainly did not with the Charge.