MORE INFORMATION
Desktop Alert is a new notification function that appears on your desktop when you receive new e-mail messages in Outlook 2003. By default, Desktop Alert is enabled in Outlook 2003. When you receive a new e-mail message, the following appears above the notification area on your desktop:
A picture of a small closed envelope.
-and-
A small message box that contains the name of the sender, of the subject, and of the first two lines of the e-mail message.
When you receive more than six new e-mail messages in a short period of time, a single Desktop Alert is displayed to indicate that you have received one or more new e-mail messages. Outlook 2003 does not display a Desktop Alert for each new e-mail message that you receive in a short period of time, as this may temporarily obscure a large portion of your desktop.
http://support.microsoft.com/default...roduct=out2003
I'd guess the 30 seconds would be related to the above. Might try searching the registry for desktop alert. Should be able to find the value "30." Not sure if it'll accept a larger number.