Shift to left during fade on IE

Issue Summary

I have created a simple rotor banner for a site that is currently under development. I noticed 2 things:
1) When you load the page, there is a brief flash of all the rotor items before the JavaScript kicked in and made them hidden. I have fixed this by adding the following css:
div.rotor-items {
visibility: hidden;
}
This is fine, but it seems odd that I had to do this in the first place and makes me wonder if I am doing something wrong.
2) In Internet Explorer 8, if you view the page then when the banner is fading between 2 images, the image moves to the left by 1 pixel during the fade operation. You can see this here: http://www.british-dragonflies.org.uk/

Any ideas why this might happen?
Thanks.
John