my experince using PPG PRO .

no matter how , the map will show u r in jln p ramlee whenever u open the apps . than try this .

go to map view .
wait for a sound " searching for satelite signal " until " satelite search complete ...
than u click function button under the screen . tap current position . yr position only able to locked now .
than u may start use navi to POI or any road .

p/s activate 3G network will help alot on position locking via satelite .
must use under clear sky . best to mount yr iphone on windshield .

so far , PPG quite good . quite accurate , routing fast .
only disadvantages so far is .. the things dunno shortcut ....only ask u follow main road .....