Mozilla 0.9.2 will display http://www.channel5.co.uk/channel5/technical.php (badly; the columns of the transmitter table aren't lined up). However when I select View Page Source, instead of diplaying the source displays a pop-up with the title "Downloading techinical.php" This states "You have chosen to download a file of type: application/x-unknown-content-type; x-view-type=view-source from http://www.channel5.co.uk/channel5/ What should Mozilla do with this file ?"

probably a dupe of bug 76816. Interestingly, the table aligns if you open this URL from Composer/Editor.

You're certainly right but this has been already filed (see the mostfreq bug 55583). Thank you for testing Mozilla *** This bug has been marked as a duplicate of 55583 ***

Sorry. Hirata is right. I was mislead by the summary which strongly suggests bug 55585 "view-source should show original source (use cached source)".

*** This bug has been marked as a duplicate of 76816 ***