Downgraded to 1.0.2 w/ ATT Sim, still no service

I feel like a total tool asking this question, but I haven't heard it specifically confirmed or denied yet.

Fist off, on my ATT account, the iPhone stuff is listed:

Quote:

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IPHONE DATA + UNL $40.00
IPHONE POSTPAID TRKG $0.00

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I had a previous iPhone and returned it to get out of the contract, then re-purchased an used iNdependence.

I tried to unlock my iPhone, it didn't work but when I upgraded to 1.1.1 it still screwed the pooch. Last night I got back down to 1.0.2. and the WiFi/iPod work pretty much as it used to.

Now, here's the problem. I'm using an official ATT Sim card (don't ask me why I tried to unlock when I'm using ATT), the iPhone plan is on my account (granted with no contract), but I still get the Invalid SIM error.

All this notwithstanding, I've read that non-ATT folks still can't unlock to make calls ater a 1.0.2 downgrade, but what about the ATT people who don't have a contract??

If you have previously unlocked your phone in any way, you cannot yet downgrade the baseband firmware. That's what they're working on next. Doesn't matter if your at&t or other. Evidently the upgrade to 1.1.1 was able to detect if you had monky'd with your phone and then stopped you from downgrading the bb firmware.

Yeah.... I suppose when the unlock failed I assumed that nothing had been changed.... poopstick!