The map does not show up (can only see the logo and the zoom bar)

From my experiment I found that if the map size is only specified by using the division size, but not in the GMap2 function itself, sometimes a "blank" map will show up. A "blank" map means I can only see the Google logo, the pan and zoom bar, and the 'Term of Use' link, but the map itself does not show up. The patch for this issue can be found in the attachment. Please note that this bug may not happen in every implementation because the module seems to work fine on the demo page provided by the module creator. However, it did happen to me and the patch definitely will not break the already working version.