Just got the package so I had to run out to try it.
A lot of USB->Serial converters install themselves as Com5 or higher. Your software when looking for an active com port doesn't look that high. In my case the converter was set to com5 so you software couldn't find the com port. I had to go into the hardware setup and change the converter to Com2 and then the software found it OK. Not a big deal but sort of annoying
I'd suggest either scanning to a higher com port number or allowing the user to specify the com port directly.
Shawn