Duff-Man says....if hughvane's suggestion does not work then you've got a couple other choices. You can do exactly what you did before but don't use 512 - try something saner like 24. You can open your com.apple.finder.plist file (in your ~/library/preferences folder) in a property list editor and change the line that shows the icon size (the terminal command would just alter this file too). If those don't work you can trash the plist file and a new one will get created, but all the settings in there will be back to defaults....oh yeah!