Thanks everyone. Problem fixed.
Sorry to not get back to the board sooner to reply. I hadn't realized that people were still posting until I got an email saying there was activity on the board. (Bit of a time delay there) Just goes to show that whatever you put on the web, stays on the web......... for ever and ever and ever.
I couldn't find the Calibre logo mentioned by Kovid in the help, but did eventually find the library button and did what "BetterRed" & "TheDuck" said, though I hadn't read the post at the time. (Like your "Staff to 4 cats" by the way, I'm staff to just one kitten (Lunna, middle name Tic) at the moment)
Again, thanks everyone.
Is it just me or are digital books just the best thing ever?