It may be that this is because maemo-launcher thing used by default in Nokia applications. This speed hack shortens startup time by having already pre-initialized process which just forks and runs user code instead of going through GTK (and perhaps also X) initilalization at startup time. Same trick is used in KDE via kdeinit.

This may mean that even renaming X unix socket may not make any difference since maemo-launcher has the old one already open.