I had the same problem on the Nexus 4. Here are my APN settings that work
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:
66.209.11.33
MMS Port:
80
MCC:
310
MNC:
410...