You may want to contact Adobe Support and see if they have a clue. Now, if you do have version 4.6 and you still can't get your files to show up and open, I don't know what the problem might be. If that isn't the version you see in the ACR Preferences or the ACR title bar, you'll need to go back to the Adobe site and read through the Elements instructions. Or, when you try to open the image, the application returns one of the following errors: 'Could not complete your request because it is not the right kind of document.
The latest version for Elements 6 is 4.6. The filename of a Camera Raw image is unavailable (dimmed) in the Open dialog box in Adobe Photoshop or Photoshop Elements. If you can open a file in Camera Raw the version number should appear on the title bar. If you don't have that menu option in the Organizer, try opening a non-XTi file in Camera Raw (if it's not a Raw file you may need to right-click on the file and specify opening it in Camera Raw, but I don't remember what the options are in Elements).
I'm not sure if you can check the Camera Raw version from the Organizer - in CS Bridge you can by going to the Edit/Camera Raw Preferences dialog box. OK, did you follow the instructions exactly for installing the Camera Raw plug-in in Elements? The process is different from that for Photoshop CSx. Wildlife project pics here, Biking Photog shoots here, "Suburbia" project here ! Mount St. Last, you can convert your Raw files to DNG, a format that Adobe can read into the Raw converter, but that other apps like DPP can not.
These apps go from upper-end apps like Lightroom and Aperture to some that are out there that are free or inexpensive but don't have the features of the "big boys'. You can use another third-party Raw converter and again save to a high-quality tiff if you need to work in Elements. You can save your Raw conversion to, say, a tiff and then open it in Elements if you need that processing.
You can install Digital Photo Professional, the software that comes with Canon DSLRs, update it to the newest version via the Canon website, then enjoy using a very nice Raw processing/conversion application that does not cost you more. You can stick with Elements-only by upgrading to Elements 8 - inexpensive and you keep using your current software. Following the assumption that what Dennis said is correct (which in all liklihood it is), you have a few options: