I don't know what I did wrong, but, as the post title says, for some reason yifanlu's jailbreak didn't work for me. Last week, I uninstalled NiLuJe's screensaver hack, then uninstalled NiLuJe's pre-3.1 firmware jailbreak, installed the 3.1 firmware, installed yifanlu's jailbreak (the only one available at the time) and then installed NiluJe's latest screensaver hack for the Kindle 3 WiFi. All of the updates were successful, per the Kindle, but none of my custom screensavers would show, only the "vanilla Kindle" screensavers were being used by the Kindle after the firmware/jailbreak/screensaver hack installations. I thought maybe, since I had the screensavers set to show randomly, that, for some reason, only the "dead author" screensavers were being chosen, but when some of the Amazon screensavers that I had
not included in my linkss folder started showing, I knew that the hack just wasn't working.
Yesterday I uninstalled the screensaver hack, uninstalled yifanlu's jailbreak, installed NiLuJe's jailbreak for 3.1 firmware, reinstalled the screensaver hack, and now all is well.
As I said, I am sure the reason yifanlu's jailbreak didn't work was due to operator error, since it seems to work for everyone else,

, but I wanted to post my experience just in case this might help someone else with a similar problem. Mind you, it could just be that somehow when I installed the screensaver hack I screwed it up - though how I could screw up dropping a file in the root directory I don't know

- so yifanlu's jailbreak had nothing to do with the problem. Anyway, everything is working now.
@ NiLuJe and yifanlu: Thank you both for helping all of us out. I hope you both realize how the community appreciates the thoughtful programming work you do. We certainly benefit from it.
Holly