Because 13.04 is so new, a lot of the PPA's haven't been updated with the file structure that 13.04 expects. However, most of the software will still work if you pull from quantal sources instead.

1. Add the ppa sudo apt-add-repository ppa:yourppa/blah as usual (You're only doing this to get the gpg key really)


2. Open software centre.


3. Menu > Edit > Software Sources...


4. Go to the "Other Sources" tab in the dialog that opens


5. Uncheck the source that you are trying to install from but note it's location


6. Close the dialog, and open a terminal


7. In a terminal sudo nano /etc/apt/sources.list

Add a line that pulls from the quantal version of the repository:

deb http://ppa.launchpad.net/yourppa/blah quantal main

Now sudo apt-get update and try installing your software again.

This is only a temporary fix because eventually (hopefully) the ppa will be updated to include raring releases. So at some point you may want to check the ppa to see if raring has been updated and remove the line from sources.list and recheck the ppa source in the software sources tab.