Along one of the long edges of the CompactFlash card there are 40 tiny holes where the communication pins inside the card slot plug in. The flash card shipped with every OMNI has a small tactile bump placed on the face of the card near the opposite long edge (i.e., the trailing edge). Insert the flash card with the holed edge in, and the tactile bump facing away from the OMNI’s keypad.
When the card is inserted correctly, it should enter the card slot with very little pressure, then stop when it is flush with the side of the OMNI. Apply a little extra pressure (say, enough to press a thumbtack into a corkboard) and the card should seat the rest of the way (about one eighth inch) and stop.
If your flash card does not have the tactile bump, feel along the non-holed long edge for a small lip. When inserting the card, this lip should be facing in the same direction as the keypad.