I use Lego Roverbot over XBee + Arduino UNO. It works. http://www.christian-elektronik.de/027.html 
One Problem: I want send same time to Roverbot/PC2 from PC1. Like Earing. See Picture
How to comminicate between PC to sending/receiving commands? :?:
Please show us the register settings on the modem configuration tab, of all 3 Xbees. You can save the settings to a text file. “Save Profile” button, it becomes a .pro file, but it is just text which you can open with notepad. Post the contents here. (within [ /CODE] tags please)
Which XBees? Series 1 or 2?
Which firmware (this will ID the XBees)?
In general set the sending XBee’s DH & DL to the address of the XBee that is to receive the data.
