Downloaded Dashboard Widgets won't run, Help.

Question

Can't figure this one out. Widgets that come with Leopard run fine. Any I download won't launch. I have 4 user accounts, all have same problem. I created a new user account and the downloaded widgets works fine.
So, not sure what happened but all users created prior to a certain point don't work, any new users now seem fine. Anyone else seen this? Any ideas on how to resolve?

Answer 1

Most of the widgets in Dashboard weren't working for me. So far as I am aware, this problem started when I tried to add new third-party widgets (downloaded through Apple-Downloads) after upgrading from Tiger to Leopard.
This is what got things working again -- and was much easier than an archive and install:
1. I took a screen shot (command-shift-3) with dashboard open to make a record of widget placement.
2. I disabled dashboard with DashboardSwitch (http://braintrigger.com/software/DashboardSwitch).
     (It might be that a restart would have done the same thing -- but for me this was easier.)
3. I removed all plists with the word "dashboard" or "widget" in its name from User/Library/Preferences, and left them in a folder on my desktop.
4. I enabled Dashboard with DashboardSwitch. (I believe it's the case that if you use this program to disable Dashboard, you cannot start Dashboard though the Dock until it's been enabled again with DashboardSwitch.)
     (For those who simply restarted in step 2, I'm guessing all you'd have to do at this stage is to open Dashboard normally.)
5. With the old preferences removed, Dashboard loaded with only the default widgets open. I clicked the plus symbol, removed those I didn't want to keep, and began adding back widgets, starting with ones originally supplied by Apple, and waiting after each one to be sure it was working. If something didn't work, I removed it and went on.
6. When I was done, only two widgets still wouldn't work.  It turned out both were only designed for Tiger, specifically, and not for Leopard. One I updated -- after which, it worked fine.  The other had no update for Leopard, so I had to replace it with something similar.  
7. I reset preferences on the flip side of my widgets, then used the screen shot I took in step 1 as a guide for putting things back in place. (Yes, that's finicky -- but I liked them where I had them.)
8. After I had everything running the way I liked it, I trashed the folder with the old widget and dashboard preferences, which I had left on my desktop.
Everything's working fine now.  I hope this helps someone else.