I have just purchased an HTC Thunderbolt. I need to be able to VPN to my corporate network using the phone. Now, the only way I can get this to work is by turning off LTE 4g. I do this by going into the secret menu *#*#4636#*#* - phone preferences then selecting CDMA auto PRL. This switches into perm 3G mode and I am able to VPN. But, if the LTE 4G is enabled VPN never connects. I don't understand this. I would love to be able to LTE for vpn since it's insanely fast! Please help me figure out this crazy issue. Thanks!