OLPC Policies Question Concerning Upgrading Default Installed Software

[anthony at evolutionindesignz.com]

Does the OLPC project have any policies against upgrading the default 
versions of the software installed on the OLPC laptop?

In particular, we are having issues with XULRunner 1.9.1.9. We are 
considering unstalling this version and replacing it with XULRunner 8.0.

i)Does the OLPC project have policies against this particular upgrade?
ii)Are there any potential problems that are known that would be 
encountered? So far, we have taken into account that the default web 
browser uses XULRunner 1.9.1.9: it is presumed that replacing XULRunner 
1.9.1.9 should not cause problems in browser functionaltiy. Are there 
any other dependencies that we should concern ourselves with(assuming 
that it is not against OLPC policies to perform the upgrade)?