I tried to install ThermIQ to my DreamPlug (Debian 6.0.4) and encountered the same problem as you did at the beginning. The device is recognized and the memory card mounted, but usbserial does not create ttyUSB0 or any other tty port for the device. My brother tried my ThermIQ in his Linux laptop (ArchLinux) and the result was exactly the same. usb-devices shows about the same output as the one you posted here.
I also tried with Windows where the device is recognized and drivers install without erros, but check_install.php page loads forever when I change the COM port from the default COM2 to COM5, which according to Device Manager is ThermIQ Composite Port.
How did you changed the loggin interval from 2M to 1M if the device was not recognized?