I'm having an issue with IE7 in two websites (haven't checked 8) the lightbox is only covering half the screen - you can scroll down and you can see the webpage behind it. The first is here trickstar.co.nz/AMS/gallery.php click on a gallery to view the contents.
The second www.rv-rak.co.nz/FAOTB_single.html.

It works fine in firefox and I have used twice it successfully before in IE7. Here is one of the working ones sweetstreet.co.nz/Photos.php?cCategory=customer I have a reset stylesheet but add this to style.css that overcomes that.

table{
margin:0 auto;/*overcomes reset stylesheet*/
padding:0;
border:0;
vertical-align:baseline;
}

I really don't know what I've done differently this time.

I've just tried the most basic page and lightbox setup and the problem is there.
trickstar.co.nz/ams/workingonit.html

I've just tried again. This time I created a new site and created a basic page with a lightbox - same problem. I tried the basic page in one of my existing sites where the light box works and it worked. My working light boxes were created last year. The ones that don't work were created this year in the last few months with version 1.0.11 I don't know what version was used at the end of last year.

Hello Phil,

I just what to confirm it is a bug within the extension that reflects only IE7. We are in progress of eliminating it.

Thanks for that.

You probably know this but the problem is in here dmx.lightbox.js somewhere. I transferred this from my older working versions and the problem was fixed.

Hello all, fix is on its way.

There is mention of a positioning bug in IE7 on a blog for thickbox:
jamiethompson.co.uk/web/2008/03/17/thickbox-31-ie7-positioning-bug/

It mentions that some revisions of IE7 incorrectly return the substring “MSIE 6.0″ in the user-agent string.

I know you said you are working on this. I'm not sure if you had already come across the above mentioned quirk, but thought I would pass it along.