Rename RAW file extension?

I renamed the Phase One raw extension from .TIF to .raw - I have my reasons.

I have selected the option of recognizing all file extensions in my preferences, When I check the finder, the renamed files are sitting in the captures folder but not showing up in the program as preview thumbnails to work with. Does this mean I cannot reprocess these files at a future date unless I change the file extension back to .TIF?

Help.