Here's what the site host (site5.com) says:
Unfortunately, I can confirm this is not going to be a problem on the server itself. 755 allows full read/write permissions to the folders and files.
At the present time though, there are no errors in the httpd or php error_logs, so the server itself is not throwing errors when you attempt to remove the files through the script itself.
I would recommend letting the script developer know that we are using SuPHP and 755 gives full read/write permissions.