"In case the answer would be of interest, the answer appears to be that this is 
a feature of Firefox"

Thank you, Randy - this is something I've been wondering for a while now but 
never got around to asking about.  Your fix worked a treat.  :-)

Now, can someone answer another query along similar lines please?  When viewing 
the archives, why is there no change in link colour after I've viewed a post? 
Back when we were using an older version, links changed colour after it'd been 
accessed, so I could keep track of which posts in a list I'd looked at, and 
which was the next in line.  All links are now in black.  Is that a "feature" of 
14.4?  I get the same whether viewing with Firefox or IE.

Kind Regards,
Wendy Howard