You can clone with
HTTPS or Subversion.
013-04-07 00:16:12 +0000: Sparkle Error: An error occurred while downloading the update. Please try again later.
2013-04-07 00:16:12 +0000: Sparkle Error (continued): too many HTTP redirects
If I type the URL it is trying to use it downloads the file. It does download the for the appcast.xml and the release notes HTML without errors.
I found the solution. I believe that a file was left in the local or remote cache. Once I changed the code below it works perfectly now. It was failing 100% of the time before.
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[updateItem fileURL]];
[request setValue:[updater userAgentString] forHTTPHeaderField:@"User-Agent"];
download = [[NSURLDownload alloc] initWithRequest:request delegate:self];