After using unity for at least 2-3 hours, whenever I try to close it, it doesn’t (application doesn’t respond).
This has happened since 4.3, and last patch didn’t solve the issue.
Is it some kind of memory leak or it’s a local issue? Maybe one of the assets I’m using?
Are you connected to an Android device? If so, it could be because Unity is waiting for the adb.exe process to close and it doesn’t. You’ll have to kill that process manually for now.
Any way to bypass that? I need the droid SDk running
I think it’s a current bug about to be fixed in the next release. For now, just manually close adb.exe each time you’re finished with it.
Tnx, this solved the problem for me 
This should be fixed in the 4.3.7 p1 release: http://forum.unity3d.com/threads/246198-Unity-Patch-Releases