Hi!
I've got a Sagem Modem: http://www.cooking-hacks.com/index.php/gprs-quadband-module-sim900-for-arduino.html
And I'm using a micro-SIM Card 3G 128. To test it I'm accessing a webservice that increments when the modem reaches a webmethod.
Well, the thing is that nothing happens. The webservice does not imcrements the variable I prepared to do so. I' even detached the antenna from the modem and the result was the same.
To a surprise 
of mine i tested the same code with a mini-SIM Card 64, still with the antenna detached. And it works perfectly!!! 
Tried to use the antenna but it didn't work. So, i retested without it and it worked fine.
Can please, please, pretty please tell why did this happened? Or why the modem doesn't work with the micro-SIM Card?
I really need to understand this. :~
Best regards and thanks in advance.