Loading Plug ins

I just got PSCS4 after having previous versions back to PS6. I'm trying to load my plug-ins (such as those from Flaming Pear) but the program doesn't recognize them. I've re-downloaded all of them to make sure they're compatible, dropped them into the filters file, and checked the file path in preferences to make sure it's correct. When I open the program, only the default filters appear. None of the outside vendor filters will load. Does anyone know how to solve this problem? Thanks in advance.

You said filters file, it should go in the plug-ins folder.

The default path is PSCS4>Plug-ins>Filters. I've tried them in just Plug-ins, in Plug-ins>Filters, and in Plug-ins>Filters>Filters with the preferences path set to match. They still won't load. In PSCS2, I dropped them in the Plug-ins folder and they worked fine. Nothing I do in PSCS4 seems to work. Any ideas? Thanks.

I wish I could help but since I'm still using CS3, I'm at a loss. I assume all the filters are compatable with CS4. Maybe you'd have better luck finding an answer on the Adobe PS forum. http://forums.adobe.com/community/photoshop/photoshop_windows

Thank you for your help and the link.