Yes. By default, Ensymble-generated SIS packages do not have any capabilities. Symbian 9 and newer only allow network connections from programs which have a "NetworkServices" capability. See the document "Testing and Signing with Symbian Platform Security" from Forum Nokia for details.
Originally Posted by paskajooseppi
Add the following to your Ensymble command line options. It turns on all capabilities that the self-signed Python Script Shell from Nokia has: