Yun Sketch does not run when wifi network is changed

My question is that "how do i keep the sketch in memory after changing wifi networks"?

I have a yun with a small sketch that sends data to my server. I can connect to the yun over wifi and upload a sketch. The sketch works fine at this point. If i unplug the yun and take it to my office and plug up the mini usb to a different computer (for power), the sketch seems to not be present anymore.

I have to reupload the sketch at the new wifi location and then it works fine again.

Thanks in Advance.

I found the answer here: http://forum.arduino.cc/index.php?topic=193911.0, the second thread. Thanks.