I use Irfanview mainly because of it's batch resizing and renaming abilities. Can resize 50 photos in a minute. It is also very fast to crop photos. Never mess with the color properties or anything else so is perfect for me.

Test
 

Or not.

Back to the original post - finally tried what you suggested Bazza and put a reduced size and full size image up for comparison. Full sized image looked fine.....but at over 8 times the size of the 'full sized' ones you posted it made the rest of the thread disappear to a narrow band down the lefthand side of the screen. Did come out in the proper resolution though and looked the same as the original on my laptop does.

Guess I need to start reducing the size before uploading rather than relying on Flickr's resizing to do the job if I want to keep the resolution the same :thumbsup: