One Android app notes: "The Android 4.0 + blocked the ability to save APN settings for cellular networks by external programs. Only the system programs have access to the APN configuration. The program installed as an external program, unfortunately, in these versions will not work."
I got these settings from straight talk customer service. They worked perfectly on my atrix 4g and now my atrix 2. It's been a year and i didn't remember them, so here they are copied from my phone. Let everyone seeking to use these phones on straight talk in the future now know what they are.
Name: straight talk
APN: att.mvno
Proxy: proxy.mvno.tracfone.com
Port: 80
Username: not set
Password: not set
Server: not set
MMSC: http://mmsc.cingular.com
MMS Proxy: mms2.tracfone.com
MMS Port: 80
MCC: 310
MNC: 410
Authentication type: none
APN Type: not set
APN Protocol: IPv4