I have quicktime with iTunes 9.2 installed and Windows Media Player 12 as part of Windows 7. I have also ticked Preferences>Mail>Play a sound.

However, I'm not getting any sound when a new massage arrives. There is nothing wrong with my speakers and they are on quite loud.

I have also tried replacing the alert.wav in C:\Users\Toby\AppData\Local\Zimbra\zdesktop\jetty\ webapps\zimbra\public\sounds\im with another, but to no avail.

What could be the problem?