Minecraft 1.5.2, Minecraft 1.6.1, Minecraft 1.6.2
Windows 7, Java Update 7, Release 25
This is a combined version of all the reported bugs about this.
Once a minecart going in a circle is blew up, the sound keeps playing, even when you go to the Title Menu and a different server.
Creepers will keep hissing even if they blew up or you ran away.
Waterfall sounds keep playing even in Title Menu.
Piston sounds keep playing after a piston is deleted and there is also, but rarely a ghost piston.
How to reproduce these are self-explanatory.