[quote:]I take it you introduce a small delay to allow the map to be initialised ? before applying the new center?[/quote]Yes, Google Maps does not provide the ability to know when they are exactly fully loaded and ready for interaction. Therefore it is necessary to hope that a second is enough. Although it is possible to implement a more complex test with interval checks every few tenths of a second.
As for debugging, yes, it's associated with the mechanism of start pages in jQM. Try inserting debugger; into your code before the needed line.