Hi,
I was getting this same problem. Seeing the rewrite logs I had noticed that the rules didn’t match because the files path was incorrect.
Reviewing the instalation procedure, I saw that my virtual host configuration didn’t match with wpmu instalation instructions.
I had installed the wpmu in ~home_folder/public_html/wpmu, but I didn’t create a virtual host to point to this folder.
When I fixed the virtual host configuration to point correctly to my wpmu folder, I get it working fine.
Perhaps the super-cache must be patched to work with non-virtual hosts, but in this case I think the error was mine.
I wish it can help you.
[]s
Victor
