There is another key under Local_machine i think, have you tried changing useragent? I think it would be ideal to use Olaf's example the api will be 80% faster (if not more) with no errors or webbrowser limitation. The api is probably pretty easy to use and sinc Olaf provided an example you should be able to do exactly what you are doing with a webbrowser or IE and probably even more.

If we could see the project we could help fix it or at least the function you use to display the maps.
Even if we did fix it believe me the api will save you a lot of debugging and errors.