FYI-  I noticed this while working with the beta source for the new events module:  DELETE event function works in the Edit Event page but not from the Event Detail page.  The VB code calling the delete function appears to be identical between the two pages (both ultimately call into the same function).  I have not changed Event Detail page code and the delete functionality is obviously working from the Edit Event page so I'm doubting the bug is a result from anything I've done.

I'm running DNN4.2 and VS2005 on WinXP Pro with IE 6.0.2900.

I can confirm this is the issue. 

If you go into EventDetails.ascx.vb

Look for this:

Private Sub deleteButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

and replace with this

Private Sub deleteButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles deleteButton.Click

recomplie, copy over the .dll to your DNN bin folder and reload and it should work.