Problem with RAW in PS CS

[PremierPhoto]

The last post about opening RAW in CS got me thinking...
I cannot open RAW images into CS. I tried the tip from the other post and it doesn't even give me that option.(ACR) I always get the message "could not complete...not the correct file type". In the past, I've just used the software that came with the camera. It coverts RAW to TIFF. I've never noticed any changes in the images, so that doesn't bother me. But, it's just an extra program/step before opening in PS. When you get really busy, it can be a pain.
[img]/ubbthreads/images/graemlins/confused.gif[/img]
If anyone can help me, please do.

Thanks in advance~