The termctrl.dll included in Platfiorm Builder may not support Serial Port Plug and Play.
When you opened 3G USB Modem device serial port by GemTerm and unplug the device, you'll get exception in the termctrl context.
This must be fixed by modifying the termctrl.dll code but this is beyond the scope of this project.

Remarks

When your SDK includes "DCOM" functions, the WTL 8.0 templete components may result in build error.
I made a little modification in WTL module and put it into "include" folder. You can use it when DCOM based build error occurs (just setup "include" folder for additional header location)