if you look through the nitdroid instructions, you should not be extracting sillyboot on your pc... transfer the archive to your phone (regardless of it being able to be opened using WinZip on your PC) and then work further..

the best forum to go to is the source: www.forum.nitdroid.com

everything else is just a rip-off...


Edit: on your point of the chargers, if your samsung charger can charge it faster it means the nokia charger is not in exactly good condition and not the device's fault...