Hi
I found another post that had some solutions on it,
changing the CSS in the nextgen css file to the below worked for me
.ngg-gallery-thumbnail img {
background-color:#FFFFFF;
border:1px solid #A9A9A9;
display:block;
margin:4px 100px 4px 5px;
padding:4px;
position:relative;
}
I made the margin 100px as per my thumb settings, this sorted it.
The thread that helped me was
https://www.ads-software.com/support/topic/plugin-nextgen-gallery-ie-8-issue-with-image-lists?replies=8
good luck
??