Unable to generate Ad code for Search box

[NB]

I am using php library. I am not able to generate ad code for Search
Box on sandbox using the example mentioned at

http://code.google.com/p/google-sensapility/source/browse/trunk/standaloneexamples/final/GenerateSearchBoxCode.php

It keeps giving me following error-

An error occurred while generating search box code. An internal error
has occurred. Please retry your request.

Error code i get is 0.



Thanks
Neha