Okay, have you loaded the firmware which has 3 partitions? Press and hold the "Setup" button for about 20 seconds and the unit should cycle through 2 menu screens before landing at the developers menu. Look for "HDD Status" and select, then check for "Partitions" and make sure there are three available. If so, then you have the partition for the PersonalPOI (note the exact spelling and capitalisation there).
If the DB3 file is called PersonalPOI, and is in a folder called PersonalPOI, and you have three partitions, then you could have a hardware issue.
Load an MP3 onto the SD card and see if you can play it.