Thanks for posting your details on how you were able to get 3G data working with your iPhone; I've successfully transferred two iPhones from Rogers Pay-as-you-go to Petro Can mobility in favour of their unlimited browsing plan.
However, I have just hit a snag that some of my friends who also switched to PC Mobile are also experiencing, and was wondering if you had the same problems? It seems that PCM has switched the Proxy Server IP address details for their service as of February 1 2012 and that the old settings in the APN provided by unlockit.co.nz no longer work. This change disabled all data services for all the iPhones (mine and my friends') that I have heard about.
I created a new APN using the new server settings via Apple's iPhone Configuration Utility, and deployed it myself to my iPhone 4 to test; data is working again, but it seems that PCM is now blocking most ports other than port 80; my mail app doesn't connect to send or receive e-mail over 3G, Apple's iMessage won't activate or send messages, and Skype won't log in over 3G as well. All these features used to work via 3G on PCM before the Feb 1 switchover, so I'm wondering:
1) Did I do something wrong in setting up the new APN on my device? PCM isn't being too helpful with this one. Or,
2) Did PCM start blocking ports for their 3G data again to keep us from using the services (like IMAP/SMTP, iMessage, etc.) that we were using before?
Any help you might have would be greatly appreciated in sorting this out; I'm still struggling my way up the customer service ladder to understand what's going on - the service used to be great with e-mail access on the go, and I was getting friends to move over to it in droves, but with only web browsing it's making it attractive to switch back to terrible Rogers/Bell just to have access to full 3G.
Please let me know if you're experiencing the same issue, and what you find out. I'll updated my discoveries here as well.