Good day to all.  I picked up a VERY out of date f700bt and I've had it running in my 98 Lincoln Navigaor for about a month now.  I am working through issues with the unit, using this site A LOT.  My issue now is that I cannot update the firmware on the unit.  I have the "LPUE080" folder on the top layer/folder of my SD card, the SD card is freshly formatted with FAT32, and there is nothing else on the card.  When I put the SD card in the slot on the unit, it does not start any update, but operates normally (playing music, etc).  I checked the A/V Source menu and the SD card is greyed out...basically the unit cannot see my SD card.  I thought I read somewhere on this forum that you had to "do something" (possibly the mute wire hack?) to get the SD card slot to become active, but I cannot find the same posts I saw when looking at other issues I have had.  I also thought I read somewhere that I cannot use an HCSD card...is that correct?  And today, I read again on this forum that the unit will not read certain brands of SD cards.  SO...I guess my main question is do I need a different SD card? 

Well, I think I just answered my own question.  Straight from the owners manual:

Success!  I picked up a PNY 4GB SD card and I was able to update the firmware.  However, I cannot hear any sound from the SD card when I have music on it, but that will be another thread if I cannot find an answer.