I look after a couple of sites for clients running XCart (well at least I thought I did

).
After just finishing an initial install for a new site and changing a few images etc I thought I check how it looked in IE8, as I always use Firefox myself.
Man, what's with the "flashes or page refreshes" every time I click a link. Thought I should check a couple of my more recent sites and to varying degrees they all do the same. Viewed through FF they all appear to work as expected.
As a couple of the sites are still work in project it is difficult to provide access at the moment, however you can check
here and
here to see what I mean.
I'm using PNG a lot more recently and is there still a problem with IE 7 & 8 and png files? Is this causing the odd behaviour?
Thanks to anybody who may have the time to take a look for me?
Regards
beetlejuice ____________