If I download or save images with a .png or .jpg file extension, and then in Firefox's download manager right click and select Open, they open in the system default application for viewing those file types. In other words, it works correctly.
But if the file extension is .gif, rather than using the system default application, it opens the .gif file in IE. If I select Open Folder and then open the .gif file from Explorer, it opens in the correct application, so I don't think it's a Windows issue with default program for that file type.
The issue is only with opening .gif files from Firefox's download manager, no other image types are affected.
Does anyone know why it is doing this, and even better, how to fix it?