Courtney, thanks for bringing this back to the top.
081035 , To reset filters, try this - hold down the alt key & press the cancel button at the top of the dialogue box. Unfortunately, I haven't heard of a way to reset all the filters at one time. As far as I know, each filter will need to be reset individually. This works on CS3, XP. Hope it works for you.
A "for sure" way is to use the same 3 finger salute used to fix things up in Elements.
Ctrl+Alt+Shift and launch CS5 - you will get a message box asking yes/no to delete Photoshop settings file. A yes response will turn everything back to "factory" settings, but everything, not just filters.
Might be worthwhile to save desktop workspace and/or take notes on any custom settings used.
Edit: You have to launch (double click) CS5, then IMMEDIATELY press and hold the 3 keys to get the message.