Geeetech

Hello guys!
My hardware is:
1) SIM900 GSM GPRS shield
2) XDRduino UNO

My software is:
"C:\Program Files\Arduino\libraries\GSM\examples\Tools\TestModem\testmodem.ino"
- an example tool from arduino library.

My problem is:(COM PORT received data:)
Starting modem test...ERROR, no modem answer.
Checking IMEI...Error: Could not get IMEI

My question is:
1) How to set jumpers X1 "Xduino", "RX", "07(RX)", "SWserial","08(TX)"
2) Power switch can be set to ext(external supply present) or Xduino(USB) - OK.
3) 3V CR1220 is absent on my plate. is it OK?

4) what I should do? Have you any simple test to test the plate?

Thanks for you answer.
http://www.seeedstudio.com/wiki/GPRS_Shield_V2.0#top - that's the tutorial I was searching. Very very helpful. Thanks a lot - I connected and send a message

Hello, just bought a SIM900 recently and went through the guide posted above (seeedstudio), which worked once and I managed to send a text to my mobile, but now every time I try and do it again it won't even connect to the network??? Any help would be good cheers.

P.s. I bought this to make a home alarm and right now I'm not too impressed with the board's reliability.