Additional images problem

Hi

I have recently migrated version 1.4.9.4 to 1.5.1. I have managed to set up the default store (to a degree) as my template no longer worked. However I am having a problem with the additional images being one on top of the other as opposed to side by side (see image below). I think it may be due to the thumbnail sizes but I don't want to have to resize all my thumbnails as I have a lot o products...Any way round this?

http://shockproof.bpweb.net/test/kp_scr01.jpg

cheers

Looks to me Like the thumbnail size, you should be able to edit this in the admin settings for the store under the image tab.