After being unable to solve this issue, I decided to try to implement my application using Bing Maps. I am trying to load a StageWebView with the Google Maps Javascript API inside a Flex Mobile application. Everything works perfectly when I view this in a browser (IE, Chrome and Safari) and in the Flash Builder simulators. On the actual devices I get varying results. I am using the StageWebView.loadString() method to load my code in Flex.
The iPhone displays the map and the shapes I put on it but does not allow me to intuitively interact with it (drag the map, zoom by pinching or double-tapping). It also does not display the interactions bar at the top left as it does in a browser.
On an Android phone (and the BlackBerry Playbook), I still cannot interact with the map intuitively, but I get the interactions bar, which mostly works. However, the app will not display my polylines (it does display pushpins).
On both devices, when I tap or doubletap on the map to try to intuitively interact with it, the keyboard comes up. Typing displays no text.
Any ideas on what my be the issue? Will I need to write my own intuitive interaction functions?
Through Alexander Farber's suggestion, I decided to use MapQuest's Flex/Flash Mobile API, which has proven to be very effective.