PocketMac Remote is a $10 software program from PocketMac that extends the functionality of the Apple Remote so that the little device can be used to control Keynote and PowerPoint presentations in addition to the iLife applications that can be accessed from Front Row.
In testing PocketMac Remote, I noticed on my Mac where I have both PowerPoint and Keynote installed that the Apple Remote does not advance or rewind slides if I try to open a PowerPoint presentation and PowerPoint is selected in the Preferences drop-down menu of PocketMac Remote. Clicks from the Apple Remote respond normally, however, if I designate Keynote as my presentation type, even when I choose to open a PowerPoint file. In such cases, the PowerPoint file opens in Keynote.
After discovering the problem, I submitted a bug report to the software developer using the online form.