Hardware Connectivity?

Hello, I recently purchased two XBEe 802 modules for a project at work. Following instructions for connecting the modules to a computer for communication and updating firmware, I connected the modules to a TTL-232R-3V3 cable (a virtual 232 serial port via usb) according to the attached schematic (Vcc is regulated at 3.3V, datasheet for cable can be found here: http://www.ftdichip.com/Documents/DataSheets/Modules/DS_TTL232R3V3.pdf).

Upon plugging in the TTL cable, the DIN LED comes on, and upon plugging in the modems to the breakout, the DOUT and ON LEDs come on, but “blink” between low-brightness and high-brightness at about 1 or 2 Hz.

Attempting to connect / test the XBee modems with X-CTU does not work, however, merely saying that it cannot connect to the device. Trying to input raw serial data with hyperterminal does not work either (‘+++’ does nothing). I know the TTL cable works, as I’ve tested communciations with it with a microcontroller (Arduino).

Can anyone tell me what’s going on, and how to fix it? Thank-you very much!!

Sorry, I couldn’t upload the schematic image. It can be found here: