Strange on-screen behavior with transparent images

I am making raffle tickets for my office holiday party, and they asked me to include our logo as a watermark. Each ticket was created by placing a holiday-themed piece of clip art onto the page, and then using the text tool to place the ticket number on each individual ticket.

I didn’t use master pages because each ticket has a completely different design, and the watermark cannot be place in the same spot on each ticket. So, I created a new layer above the layer holding all of the images and text for the tickets, and placed a .PSD file with transparency.

On the screen, for a couple of my tickets, the watermark “honors” the boundaries of the clip art image below it (and on another layer). This problem doesn’t occur with all of the images where the watermark extends beyond the boundary of the clip art image. Here’s a screen cap, so that you can see what I mean: [url]https://drive.google.com/file/d/0B8CRXnzzu9_hNlRLSUZHdkMyeXM/view?usp=sharing[/url]

Turns out that when I send this document to print, the watermark prints as I need it to, so this seems to be a problem with the screen only. Any thoughts about why this might be happening? Do you think it is worth posting it as a problem to the list of InDesign issues on the Adobe website?

You can test the INDD file here: [url]https://drive.google.com/folderview?id=0B8CRXnzzu9_hSVpZY3ZMNVlYeTg&usp=sharing[\url]