Unable to connect on 915 MHz

I finally got my pixhawk to go full functionality with one exception. I can connect via a hardwire USB connection but when I try to connect using the 915 MHz modems I get a timeout. I can see the comport for the modem and have tried all 57,600 and 115200 but zero luck in connecting with MAVlink. The green light is one for both modems and everything works fine, all tests pass, radio connects, GPX fix, can arm etc.

Are you on Windows? Maybe the radio is being detected as a serial mouse. Try disabling serial mouse support. http://www.taltech.com/support/entry/windows_2000_nt_serial_mice_and_missing_com_port