User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0 If Firefox is not running, and a data file associated with it is double-clicked, then it will load properly every time. If Firefox is running already and an associated data file is double-clicked, if that file has the "squared" character in the name: '²', then an error dialog is displayed saying: "The file /l:/path/to%B2/file.htm cannot be found. Please check the location and try again." Reproducible: Always Steps to Reproduce: 1. Create a directory, the name of which has the character made by holding down the alt key and typing the zero-one-seven-eight keys on the numeric keypad. You should get a "squared" symbol - a superscript 2: '²' 2. Place an html file in that directory 3. Start an instance of Firefox 4. Double click the html file you placed in the directory. Actual Results: An error dialog is displayed saying: "The file /l:/path/to%B2/file.xml cannot be found. Please check the location and try again." Expected Results: Load and display the file.

Not sure if this was "file handling" or "os integration".

*** This bug has been marked as a duplicate of 263570 ***