empty spaces are inevitable unless we can convince the userbase to post a full row of images at a time 

1. the layout could use some adjusting

2. the size of thumbs seems to be a percentage of the image size rather than a fixed size

3. the bars do seem to be missing the "collapse" widget

was that the same theme on FF.com ?

300px x 3 pics x 21 per page looks good on my screen
4 pics per row would hang off the side wider than my screen

I could add a "width=" value to the html img tag generation so when thumb size is changed it displays all thumbs the same width.

There is no point in comparing FFV1 to this site.  It's running a VERY old version of both SMF and the Gallery, so many things will be different and there may be no way to duplicate them.

Number of thumbs per page can't be a multiple of number of thumbs per row to avoid empty spots because it is set as an absolute number of thumbs.  There is no setting for rows and no variables or calculations are possible when setting that.

Christian did a lot of customization to it's code base which I am unwilling to touch with my sketchy knowledge of php and server side programming.

We can ask many things of the people who made the gallery, but as you may recall from our set-up days, they only answer certain types of questions and they don't give complete answers - they expect anyone customizing it to know what they are doing with php, and I do not   :\'(

As for the css solution - I am even worse with css than php, so I wont touch that either!

Maybe a braver soul than I is willing to try.  But I am still not going to be the one to implement that sort of thing   

I could add a "width=" value to the html img tag generation so when thumb size is changed it displays all thumbs the same width.

done! when thumb width is adjusted in admin area for gallery the html img tags now actually get generated with "width="gallery_ thumb_width

just now looking at "collapse" for gallery categories, seems a bit more complicated 

oh well, you can't have everything... just accept that thumbs smaller than the width value in settings will be scaled up, like soc's "Adult content" thumb 

I think in the forum maintenance page we can regenerate thumbs but I'm not terribly concerned about it right now, I suppose it could test for the larger of width or height and scale that instead of just width, but that's a bunch of testing and different bits of code based on conditions etc. maybe I'll get to it later.

edit: hmm... after looking at the gallery layout now I think you're right so this is on my todo list, plus doing little things like this helps me get my head into the code