How I made the larger thumbnails in my galleries.
Edit the following file ind your cmsms dir:
In this file, you edit the thumbnail dimensions.
I use the following setting.
To make thumbnail appear larger in the albums, I also edited the following file, to get the autothumbnailsize function to return a larger value.
I editied the following in the follwing file:
A thing to notice.... When you change the size of thumbnails, remember to readd the images to your albums, since it stores the dimensions of the thumbnails to be used when displaying them. (I used quite some time debugging on this.)