It came straight from dell's website, and I have all the drivers still installed. I did change the power settings though, but I wouldn't think that would change it. Are those Fn keys mapped in the registry somewhere? I know that the media keys on my desktop keyboard are mapped in the registry.
Actually, it depends on what you changed. It may well have something to do with it. This is only a trigger key to impliment some power setting changes as defined in the power settings configuration. If you turned those settings off, it will trigger nothing and hence appear to do nothing. To see it, you likely want to setup the power settings to Portable/Laptop, with the monitor, hard drives, and most of all system standby set to some time - 10 minutes maybe. If this does what the buttons on my keyboard used to do, it will shortcut those times and put it in a lower power setting in less than the 10 minutes it shows.
Of course you can always remap it yourself to whatever you want.
Me, I would just have it open the properties so I could change them manually, or use it as a hotkey for another power manager to change to a different saved scheme all together.