This is current as of RC-SP1 version of OpsMgr 2007.
When you create a repeating event monitor, and use the GUI to add in some Alert description variables, such as event ID, Description, etc... you will find that they do not work. Below are the correct variables to use for repeating event monitors:
EventDisplayNumber (Event ID): $Data/Context/Context/DataItem/EventDisplayNumber$
EventDescription (Description): $Data/Context/Context/DataItem/EventDescription$
Publisher Name (Event Source): $Data/Context/Context/DataItem/PublisherName$