I had a Pi B+ V1.2 in my junk box so installed piaware. If I boot up without the ProStick+ plugged in, I get a DHCP address and I can browse to the web page and see that status is as expected - piware running, connected to FlightAware and, of course, no radio. When I plug in the ProStick and power up, it gets hung apparently trying find the ProStck+. The red LED and the LED on the ProStick flickers every few seconds and I never get a network connection - no activity on ethernet LEDs. The ProStick works great on my Windows 7 system. So is the Pi B+ V1.2 a no-go and I need to pony up get a more current version or might there be some other problem?
Try a better power supply. The Red LED blinking indicates a power supply issue.
It could also be that the old RPI can’t supply enough power to the FA dongle.
Thanks for the tip 
I got my cell phone
“turbo charger” and all is well now. Guess I should buy an “official” RPI power supply. BTW, seems I get a lot better performance from the piaware setup than with dump1090 and planeplotter - almost double the msg/sec and
entries in the aircraft view.