US C1300 not unlocked after Blazer

[Flash-GSM]

I recently unlocked a US C1300 for a customer and tested it with a Cellular One (Dobson) SIM. the phone worked ok, it boots up just doesn't find network (I suspect 900 MHz band as we have only 850 MHz up here). I send phone to customer and emails me that the phone boots up but gives him the 'Phone Restricted' deal. I told him to do the 2945#*# and factory reset and all should be fine. this is his reply:

"Thank you very much for your restriction code but unfortunately it didn't unlock the phone. As soon as the phone boots up it reads "phone restricted" and then it asks you for a restricition code which is where we entered the "2945#*#" and the factory default. There is a little bit of differences in the phone when we entered the code for example after we enter the restriction code you indicated to go "to menu" and there was no menu option it was already there and then you said to go "to factory reset" and it was factory default."

Any suggestions?
thx

[bungle_uk]

Use sim card that phone was originally locked to, to do the factory reset