Mouse.hide(); is being randomly ignored after one of Chrome/Opera update (perhaps it might do something with Chromium/PepperFlash?). As the result two cursors appear in Flash games (including mine) - system one and in-game one.
I keep receiving reports from players and experience this bug by myself but it seems like this problem stays for about a month now. Maybe somebody knows a ways to fix this? Or maybe it's worth starting and voting for bug report at bugs.chromium.org & tracker.adobe.com? I had no luck at chromium though.
Example is here (in main menu you will notice two cursors):
I have no idea what to do when barely visible yet still significant bugs like this one happen and stay for a long time.