I just installed the Theme Pack using wpmu 2.7.1. On a few the header's not working and the theme isn't loading properly. On more than half, the header image and other images are not loading. On install I left the themes in the main Theme Pack folder in their own sub-folders. I tried moving a few that weren't working in to the main wpmu theme folder, but that didn't have any effect.
I've made the changes to the theme.php as recommended in other threads here. The dashes in the theme names don't seem to be an issue either as several of the themes are not working don't have any dashes in the name. I've uninstalled any plug-ins that might effect.
Some of the themes in question are: LetoPrime, Mandigo, MistyLook, Primitivo, Regulus, SeaShore, Simpla, Simplr, Solipsus, etc.