Love to se the weather on your SpringBoard?
But, you can't make it work on iOS4...
Don't worry, here is how to fix it
First you are going to right-click the Widget.HTML or Wallpaper.HTML file
Now Open it with DreamWeaver (You should be able to open it with notepad/textedit too...but not so sure abou it)
Now copy this two lines in. ( see pic)
Now, save the file and ssh-it in to your device and respring your device and thats it. It should work as it worked for me.