Loading Speeds

One of our sites recently went down and was re-installed.
Everything is identical to as it was before except for a couple of add ons but we are experiencing quite slow page loading times because of the amount of images.
I realise that the best resolution to this is to reduce the size/quality of the images, however I am just curious as to why this is only happening now, after the re-installation of the base Zen software.
The pages seemed to load much faster previously even though all images were identical.
I will be looking into resizing soon anyway however for now I was just wondering if one of my add ons was possible causing the speeding of the old sites images. The only 2 addons that I can think I previously had which may/may not influence the speed was the Query Cache add on and the css/js loader add on. I currently have the QQ installed but have not installed the css/js loader.
Could this missing add on possibly be causing this slowdown or is it doubtful?
If anyone could offer any suggestions on this or maybe any other ways to speed up the pages loading (other than the obvious resizing of images) then this would be appreciated.
One of the slower pages is the below url

http://www.andysmotorcycles.com/index.php?main_page=index&cPath=2

Thank you

Actually, your image sizes aren't that bad, and the site load times are very acceptable here.

Also loading fine for me. There is an error message that appears at the bottom, though:

2008 MySQL client ran out of memory
in:
[select categories_id from zen_categories where parent_id = '323']

I am at work so its probably just a slow internet connection or something. It takes about 3 to 4 seconds after the page has appeared for mos of the images to appear. Il try it at a few different locations though just incase.
I am very keen to see what this mysql error message is all about. Iv searched everywhere and have been unable to find any errors. Please provide more information...

2008 MySQL client ran out of memory> Miff:

I am very keen to see what this mysql error message is all about.The error message is quite clear. And since the only way to handle MySQL memory problems is to have the webserver administrator fix the configuration, they're the proper place to direct your question.

Iv made a couple of changes now. Can you now confirm that this error message problem has been resolved. I cannot say that I have been able to see it again. Thank you.