OS X :: Disk Image Won't Open Automatically Since Last Security Update

I am using OS 10.5.8.

In the past, I could double click on my disk image file (secure.sparseimage) and it would procede to ask for password and then open.

Since the last security update, when I double click on the same file, it opens disk utility. I then have to double click on the secure.sparseimage file in the left pane.

I checked disk utility preferences and it is still set to automatically open both read only and read and write disk images.

Anyone have the same experience and possibly an explanation or solution?