Honestly, the only issue MU has with themes is if it creates thumbnails using older versions of the timthumb script.
I've got a multisite WP install (using subdirectories) with the Antisnews magazine style theme installed and enabled for the entire network. I have this theme as my current theme for the root site (/) and everything, especially the images, works fine.
My problem is when I try to use this same theme for a sub-site (/xxx/). All of the images disappear except for 2 or 3 seeming random ones. Everything else is fine, only the images seem to be affected so I suspect something's wrong with the image cropping routine that creates the homepage thumbnails or maybe the theme is trying to put them into a different subdirectory.
I came across an old post about "older versions of timthumb" and thought that might help --- or am I barking up the wrong tree?
Why would the theme crop images perfectly in the root site but then not crop them on a sub-site? Are some of the theme files getting "lost" when called by the subdirectory site?
Any ideas would be appreciated.
Thanks in advance.