OK, you must update your PRO C if you already have it installed. As far as I can tell, the changes only effect ATPRO.PRX and the others, inside the kd folder are unchanged, however, REPLACE THEM ALL, just to be safe.

Drag kd folder onto root of memory stick, select YES to all prompts. Go into the SEPLUGINS folder inside the archive, and copy just the atpro.prx into the seplugins folder on your memory stick, selecting YES to overwrite the old version.

As always, visit [You must be registered and logged in to see this link.] and download the version that corresponds to your firmware version.