Yep. Mac OS X v. 10.5.3
Minimized using [Command] + M keys. It puts an icon down in the same place safari goes when I minimize that.
I'm new to macs, so I don't know how to take screenshots, but it basically looks just like the pic you posted. Kinda weird, your machine has a little more oomph than mine, methinks. Other than that, it's just got the basic programs on it than come with OS X, so there's not much out of standard running along with DoP. Nor am I closing down processes.
If I can provide you any more information on my system to help figure out what's going on, lemme know.