I have a similar issue here, however the details of my issue is this; I have a Samsung RugbyIII (SGH A997) unlocked phone, several actually. All phones had worked fine in the past with AT&T Go Phones, I could just swap Sim cards from one phone to another with no problem as all phones were the same type and all unlocked phones, I switched over to T-Mobile about a year or so ago and when first inserted Sim card from T-Mobile to these phones all worked fine, never had any problem. I recently had an issue with one of my phones that did not want to power down properly, the back light display would stay on, so I removed the battery and Sim card and SD card and placed into one of my other phones all worked fine then a day or two later I switched the Sim card and SD card back to the original phone, still no problem. Now suddenly this phone started giving me the messages "phone not allowed #mm6 and Sim not provisioned #mm2", and comes up saying emergency calls only when trying to make a call. I have even tried going back to the other phone with the Sim and get the same thing. Everything was working fine till yesterday, first day I had this issue.
T-Mobile phone support has been of no help with this issue. I will be visiting a T-Mobile store today to try and get some help with this.
I will follow up with any information I get on this issue.
*Discussion branched and moved from Wearables Discussions to Samsung Galaxy Discussions - Marissa