do you have more details? i upgraded to GAE 1.5.2 when it came out and am using it without problem. though i always invoke it via a command line script (even though i'm on a mac right now). i'm running several differing versions of web2py for various clients without problem.
note that keep access to test data i did what i mention here: https://groups.google.com/forum/#!searchin/web2py/gae|sort:date/web2py/M_4sbSGKtoA/80gw_I0NSEYJ cfh
