Mouseover and mouseout for rectangle are not fired correctly in Google Maps API v3

Question

I have a map, and I draw a rectangle on it. Here is what I want: whenever my mouse enter that rectangle, open an infowindow, when my mouse leave, close the infowindow.

I

Answer 1

There was a change to the way Firefox 39.0 handles mouse events. See issue 8278 in the issue tracker

Project Member #4 enoch...@google.com
Thanks for reporting this issue. Indeed, it appears that Firefox 39 has made changes to its mouse event, which is causing the API to behave incorrectly.
Status: Accepted 
Owner: enoch...@google.com 
Labels: Internal-20820906 

Note that users have reported that v=3 (the release version) is working correctly and this issue only appears in v=3.exp (the "experimental" version).