I've rarely seen a company just kind of NOT KNOW how to solve an issue like this and seeming NOT HAVE THOUGHT ABOUT IT prior to me brining it up several years ago. Crazy.
I called them (Win 7 64-bit) and they said "Well, you can use your own soundcard now, so just have Pod Farm 2 use your soundcard." That was a pitiful answer, because the Line 6 setup gives us such nice low-latency and whatnot.
I have to call up the driver in Windows, ask it to make a tone in the device, then the Windows driver starts using it in 48/24. I use it standalone exclusively because ASIO drivers don't work with two devices simultaneously in a DAW and my main ASIO device is a very nice soundcard that handles my audio in Sonar.
ASIO devices CAN be used simultaneously by different programs at the same time, so I boot Sonar for recording and boot Pod Farm 2 standalone, then record through the audio outputs of the TonePort instead of by USB. Sure, it's a longer signal path, but I've never noticed any degradation. I DO, though, want it at 48/24, so I have to do the Win 7 driver call-up thing each time to get Pod Farm 2 to use it at the higher rates.
What is pitiful is that Amplitube 3 and many other software modelers HAVE THE SETTING IN THEIR SOFTWARE, making is simple as pie to just set to 48/24. Line 6 told me "Oh, we left that to the Windows system to set." Well, sorry, but it doesn't work.
So, go to your Windows audio devices and set it there, then tell it to make a tone on the device. It will reset to your desired rate. After you close it, it won't come back that, so remember that.