Hi there
I just find a little time and add a new behavior of plugin call for placemark.
Now, when you call plugin for one placemark (zhgooglemap-marker), I forced disable placemark list, because it is not needed there (one placemark on map).
PS from this time plugin for joomla 2.5 is stopped in development (adding new features), due to joomla 2.5 stopped in support.
Only plugin version for j.3.x will continue developing.