You didn't remove your debugging code in OnEvent_Initialize.
You have "Debug.DebuggingWindowVisible=1;" there... kind of annoying to have that pop up.
EDIT:
wshshell.RegWrite("HKCU\\Software\\Zwobot.com\\Streaming Sound Plugin\\PlaySounds", OnOff, "REG_DWORD");
It's probably better to store your settings at
MsgPlus.ScriptRegPath.