anyone have experience it?  T-mobile model unlocked, but inserting ATT SIM card ?

When you inserted the the foreign SIM card in the phone were you asked to enter the PIN/Unlock code?  Did you enter the code the rep gave you and was it accepted (it should take you back to the home screen).  The phone is fully compatible with and AT&T prepaid SIM so my suspicion is the SIM is not active instead of being rejected by the phone.

Make sure the phone has the latest software (updated via Zune) to ensure you get all the correct data settings as well.

@Snuffle_misa: Were you able to use it with ATT? I am having the same issue. I purchased a new unlocked from DELL but ATT sim is not working. Please share how you got it working?

Same here, have the invalid sim message, error 213 in the diagnostic screen.. with a properly unlocked (by Dell) device

My problem got resolved by getting the new AT&T sim. It looks this phone some how not recognizing old AT&T sims.

Hi guys, i bought a dell venue pro from the states via ebay and i live in the uk, its locked to t mobile and i've been going to the ends of the earth to get it unlocked! how can i get dell to unlock it for me? it seems possible, it wouldnt make much sense if the manufacturer couldnt unlock their own phone! 

Thanks 

Please send an email at UnlockCodeRequest@dell.com with your service tag and IMEI number.

Thanks,

Rahul

Hi Jerry,

after loosing many days trying to unlock this phone, i resigned to send it back to the seller...

I have check with Dell support, but the reply the standard answer "please check on the support page of Dell Venue Pro"...I also check with the support of an unlock code seller, but no sucess.

Are you also with an European carrier?

Gael

YES it's possible!  I just got a t-mobile optimized DVP and called Dell Mobility tech support to get an unlock pin.  It took them three days, but they sent it to me.  I was then able to plug in my AT&T sim card and get up and running immediately.

Cool right?  There's a catch.  Because our tmobile DVPs are build with AWS data bands, they will NOT work on AT&T's 3G network.  Long story short, you can unlock it with a little patience and resilience via Dell Mobility support, but you will only get 2G (EDGE) data speeds. 

People have this same kind of problem unlocking iPhones for tmobile's network.  Even today you can unlock an iPhone 4S and put it on t-mobile's network, but you might as well be using an original iPhone because you'll only be getting 2G data speeds!!!

i can unlock it ,in 10mins