Okay, so I've troubleshot (sp?) a few issues today and figured them out. Wanted to pass along what I've learned to other novice themers/iphone explorers. 1. trying to get slider themes to work on iPhone 4. I downloaded a bunch of slider themes, checked them in winterboard, and resprang with no results. Ended up being that I needed to change the "bottombardknobgray.png file" to include @2x for them to work for the iPhone 4. Also, slider pngs for previous iPhone versions have a smaller resolution so you'll need to change to a resolution of 142x94. Any way, hope this is useful for some.