Image uploading again.

I can now upload images in firefox again. (see this post for when it failed).
I ran firefox in safe mode using firefox -safe-mode and I was able to upload an image to flickr ok. This meant that the problem was a conflicting/corrupt/flakey extension. I went through my list of extensions and deleted some that were duplicate in other extensions and tidied up the ones I no longer needed. I removed informeter, livelines,tab clicking options, undoclosetab, sitebar and evernote extensions and the problem went away. I reinstalled sitebar and evernote (as I use these) and the browser doesn't crash.