I upgraded my virgin contract to get the galaxy s2, I fidgeted around but couldn't connect to to mobile internet even though I had the correct settings... That night i connected to wifi in my home, and the next morning I realized I could connect to virgin mobile internet. I figured Virgin just sorted it out somewhere during the time I used wifi. My girlfriend switched to Virgin at about the same time to get the galaxy s2, and she also coudn't connect. Two weeks later she visited me and still couldn't connect to mobile internet, nobody at Virgin could help her. I hooked her up to my wifi, as this was the only thing I did to my phone that I didnt try on her phone. After that, bam. Mobile internet. Im guessing phone needs to download some update or something to connect to the virgin network.
PS I downloaded dataEnabler widget on both phones while on wifi, but i dont think it has anything to do with it. Awesome little widget though.