Can't set up gmail account on this computer but I can access it via Firefox. Have set it up on my other computer.

Have two gmail accounts - rwalling395 at gmail and jwalling395 at gmail Both are accessible using Thunderbird on computer 1 using Thunderbird and/or Firefox. Can't access jwalling395 at gmail on computer 2 using Thunderbird. I get an invalid password message,yet it works on this computer using Firefox.