I recently got Litestep and was able to get the VolumeUp, VolumeDown, and mute to work on my laptop. But for some reason, the right arrow key also lowers the volume on my laptop. What could be the problem?

It's likely that somewhere you've got a setting that maps the right arrow key to a volume control "bang" command. Try "grepping" (Windows Search, Agent Rancack, whatever you like to use) the word "volume" and/or "hotkey" in your config files - both the theme and your personal folder.