Ok, gave it a few days with absolutely no Powerboost on a fresh flash of MIUI 1.10.21 to make sure that I had no data issues switching back and forth between Wifi and 3G. Everything was running great.
Just now installed the newest PB2.2 and toggled all mods on except for the CWR hack and hard key lights. But now it's back to the data problems.
It's not isolated to Wifi or 3G. If I boot up the phone with Wifi enabled, Wifi works fine. If I disable it, the 3G icon comes up and shows to be passing data up and down, but every program I launch says there's no data connection. So then I reboot the phone and it comes up with 3G data connections no problem. But then if I enable Wifi, it connects, but no data connection on any applications until I reboot again. So per boot, I only get data from one or the other, whichever is active on boot.
Any ideas?? This is the same problem I had with PB2.1, and it's not specific to MIUI 1.10.21 as it gave me the exact same issue on 1.11.9 and on VorteX RC1.