With the tweaking of the servers that the admins have done, I am not sure what might have changed.
For awhile, some people could not get php cron jobs to run on some of the free servers. Almost like the PHP cli was disabled.
Ideas:
1. Recheck the path. On Chopin it is /usr/local/bin/php
2. If nothing else works, if the .php files are visible from the Web, use wget -q as a temporary solution.
3. Remember, only one cron every 5 minutes.
4. If you are still having problems, post back (include which server you are on).