Do you ever have speed issues with your themes and plugins?

HI there, sorry to bother you, but, I seem to be having enormous speed issues with my installation.

I am trying to set up an appointments multi site.
I have installed it on my server and after a few initial page loads, subsequent pages can take 30 seconds or more to load the simplest of pages.

I have installed a similar setup on another server and it seems a bit faster but not really quick.

I am wondering if I have some configuration wrong?
The problem domain in question is appointmentbookpro.com

I have set up a similar one at dotcomslash.co.uk for comparison which seems faster.

Please don't laugh at my set up as it is in the very early stages of development and I am still learning the plugins and theme features.

If you need more information just ask.

Thanks
and regards, Wayne.