First off, DPP is Digital Photo Professional, it's from Canon. Not the prettiest app, but dose a nice job converting raw files. Second, if you have PS CS2, and have installed the ACR 3.3 plugin correctly, cr2 files from your 350d should open fine. I suspect that it was either installed improperly or the downloaded file was corrupt. Open Photoshop CS, and click Help>About Pug-in and look for Camera Raw. Click on that and note what version it is. It should be 3.3. If it isn't, download the latest ACR from Adobe.com, rename whatever Camera Raw file that is there to Camera Raw.8bi_BAKUP, and extract the Camera Raw.8bi file to: C:\Program Files\Common Files\Adobe\Plug-Ins\CS2\File Formats folder. Close any PS windows and restart PS. If you still can't open a cr2 file, contact Adobe support.
Apparently there was some conflict between the versions of ACR and of multiple PS versions installed. But now I can open .cr2.
My remaining issue is whether or not I can see the image when I view them as thumbnails rather than clicking each one and seeing it in the preview box.

