Solved the JSON caching problem for bulk acceptance.
This is done in the same way as it is done in AJAX calls by appending the current time as a GET argument.
Patch by: Mario Ferraro, Lennard de Rijk
Reviewed by: Lennard de Rijk
A list of bugs is available in the Google App Engine SDK project on Google Code.
The issue tracker is at http://code.google.com/p/googleappengine/issues/.