Remote Xbee can only receive signals, but can't send them

[ktreppendahl]

I've wired up two xbees to arduinos with a pair of adapter kits I bought from this website. I'm using a program called Firefly to communicated to the Arduino, but basically, Firefly writes sketches for Arduino.

Both radios are working- both lights turn on when I plug them into their breadboards, and I have been able to send signals to my remote xbee from the stationary one. I can turn a LED on the remote xbee on by pressing down a pushbutton on my stationary one. However, when I try to read signals from the remote xbee, nothing happens.

Strangely, the remote xbee and stationary xbee are only communicating when I have them wired in this fashion: the stationary xbee (the one connected to my computer) is plugged into the arduino so that the RX on the Xbee lines up with the Rx on the arduino, and the tx on the xbee lines up with the tx on the arduino. The remote xbee, however, has the RX line of the xbee plugged into the TX line of the arduino, and viceversa. If I wire the modules any differently, I can't write signals to the remote xbee at all.

I've also noticed that, on the panel of the stationary arduino, both the TX and RX lights are on. On the panel of the remote arduino, only the TX light is on. When I push the button, the light next to the L symbol on both microcontrollers lights up, as does the LED.
When I press the pushbutton on my remote arduino, nothing happens. No signal is sent. I know it isn't a wiring problem, because when I switch the modules (designate the "stationary" one as the remote one and viceversa), the same problem occurs. I can send signals, I can't read them.

If you have any advice about how to solve this issue, I'd greatly appreciate it. Thank you--

[adafruit_support_bill]

the stationary xbee (the one connected to my computer) is plugged into the arduino so that the RX on the Xbee lines up with the Rx on the arduino

And how are you communicating with the computer? If you are connected via USB, the Rx/Tx lines on the arduino are also in use by the on-board USB/Serial interface.

[ktreppendahl]

Yes, I am connected via usb. I'm not sure exactly what you're suggesting though. Could you provide a little more explanation?

Thanks

[adafruit_support_bill]

The serial side of the on-board usb/serial converter is connected via the Pins 0 and 1 (Rx & Tx) of the Arduino. If you are using serial communication to the host PC at the same time you are trying to communicate with the XBee, there will be a conflict.

http://arduino.cc/en/Main/ArduinoBoardUno

The ATmega328 provides UART TTL (5V) serial communication, which is available on digital pins 0 (RX) and 1 (TX). An ATmega8U2 on the board channels this serial communication over USB and appears as a virtual com port to software on the computer.

[ktreppendahl]

What other ways are there for me to communicate between my pc and my arduino, if not with a usb connection?

Just to be clear: I have a usb connected to my arduino, powering it and communicating with it. The x-bee is connected to that arduino. Another xbee is connected to another arduino that is powered with by lithium batteries.

Thanks again for your help-

[adafruit_support_bill]

You can communicate on any two digital pins using NewSoftSerial. The example in the XBee tutorial shows how to communicate with the PC and the XBee at the same time:
http://www.ladyada.net/make/xbee/point2point.html