The problem seems to be linked to restarting. What happens is that if you right click on the addon and select "Find Updates" it finds an update and asks you to restart. Even if you close the browser and reopen it, it won't work - you need to click on the restart link in the addons pane. It then works for that session, but if you close the browser and reopen it, the problem starts over and the addon is marked as incompatible. For whatever reason the install doesn't seem permanent.

This is happening on multiple computers, but just in case anyone finds a correlation, other addons I have include (all of them at latest versions):

Tree Style Tab, Colorzilla, Firebug, Web Developer, FireFTP, Read It Later, Tab Counter

I also have two other incompatible addons: Adobe Acrobat - Create PDF 1.0 and Delicious Bookmarks 2.1.106

Thanks for the information. Since I posted my original message 1-Click Weather has cycled between working and incompatible twice more. In looking at my menu bar I see that right now it's off again. I'll try the find updates and see if that fixes it.

Even if it does, though, going through that every time I fire up the browser is going to be a pain. I hope Mozilla fixes whatever is causing this.

I not only hope something will be done about this problem but something had better be done about this problem or I find another solution not named Firefox.

Agreed - two machines, Windows 7 and XP, both 1-clicks worked for awhile. Additional problems with other addd-ons. FF4 is a disaster.

I did not have this exact problem, but a similar one to this add-on. I solved this problem through the MazillaZine forums. Here is the link to the post:

1-Click Weather Add-on for Firefox

[Exception... "Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsIFileInputStream.init]" nsresult: "0x80520012 (NS_ERROR_FILE_NOT_FOUND)" location: "JS frame :: chrome://1clickweather/content/js/utils/filemanager.js :: <TOP_LEVEL> :: line 233" data: no]

[Exception... "Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsIFileInputStream.init]" nsresult: "0x80520012 (NS_ERROR_FILE_NOT_FOUND)" location: "JS frame :: chrome://1clickweather/content/js/utils/filemanager.js :: <TOP_LEVEL> :: line 133" data: no]

Installed multiple times as well as the "just DL the file and drag it onto Firefox" to install it, neither worked.

Scratch that, I misinterpreted the instructions. You were supposed to drop the Megaupload's version of the .xpi file onto the Firefox window, not the original file.

Verifying that the link from princess111 and the instructions there are valid. It's nice to have my 1-click weather back :D