Data/internet not connecting on iPhone using Straight talk?

I just switched to Straight Talk Unlimited for my iPhone 4. Calls and messaging are working just fine, but my internet data (supposed to be included/supported) will never connect. Has anyone else experienced this? How did you get past this?

You need to change some setting within the phone to get internet and picture messaging to work.
If you need more help go here and look at the "iPhone" sticky.