You can find out if SATA is active by putting your 8300HD into diagnostic mode.
Here's how:
Simultaneously press and hold SELECT and EXIT on the front panel, not the remote, for about 4 seconds until you hear a "ding", then release. The display will briefly show "diag". Press exit again and your box will tune to channel 611 where a wealth of information is displayed. Use the navigation keys on the remote to scroll down the left hand contents column to view each page.
Now look for SATA. If it says something like "SATA Status: Authorized" you're good to go! Obviously, you're going to want to check that there's an open SATA port on the back of your box.
Basshive, I see you're in WI - you might want to take a look at this thread I just created at the MilwaukeeHDTV forums, specifically about the SATA functionality on the 8300HD in the Milwaukee area:
http://www.milwaukeehdtv.org/forums/showthread.php?t=6538