[hillman]

Any chance you've just got a permissions problem? When you enable debug mode in zimbrarest.cgi, all it does is read in the list of tips by fetching the contents of the directory, then call the function that prints all of the tips. Since you saw no tips in debug mode, that suggests that the print function failed. All the print function does is suck in the file and print it to stdout, so there's not a lot to fail (that said, it's supposed to return a 500 error code if it can't open one of the files)

The function that actually returns the tips is "send_all_tips". It's pretty simple perl - you could try sticking in some judicious 'prints' to figure out where it's losing the data (in 'debug' mode, you can run zimbrarest.cgi from the command line to see the list of tips - no need to access it via the web)