Programmer is not responding

Hello!

I' don't get any program down to my board!
I'm usinh Arduino - 0006 and it gives the message "Programmer is not responding."

Try #1:
There is a Rx LED on the board and this LED is not blinking while updating, but when i use
the Serial Monitor I see the blinking, when i send something down there!

Try #2:
If the board is not connected he writes /dev/com5 not connected

Does someone knows help?

thx informatics

Did you check the troubleshooting guide?
http://www.arduino.cc/en/Guide/Troubleshooting#upload