HTC Thunderbolt 4G connection problem

I've been using Android PocketCloud for several months now and I love it. It's previously worked great on my HTC Thunderbolt, but recently I haven't been able to connect to my home computer (auto-discovery) over 3G/4G. PocketCloud can see my home computer, but when it attempts to connect it actually appears to crash the phone's 3G/4G connection, i.e. my phone loses data connectivity for a few seconds and then hooks up to the network again. When using WiFi I can make the connection without issue, so I think the settings are all OK.

The Thunderbolt had a OTA update about a month ago, so it's possible there is a new compatibility issue - I'm just wondering if others are experiencing similar problems or if I have a unique situation.

I'm connecting to a Windows 7 machine using auto-discovery with NLA.

Thanks.