Trouble loading Jep plates in 540

I've had my 540 installed now for a few months and have updated the database a handful of times without issue.  However, since mid-December I've been trying to get the latest Jeppesen  Chart data loaded in my 540 and it just won't take.  I've downloaded four times to two different flash drives.  Each time the unit will load to 99% and then show an error and quit.  Even though the unit would not load the most current plates, it was at least kind enough to delete all the other chart data before it failed ... sigh.

Jeppesen thought the issue was the flash drive, so I tried a different one but it failed, too.  I always format the flash drive before uploading new data as I understand from others that that's been an issue.  Four formats, four downloads, four failures.  Any ideas?  Small caliber to the back of the unit??

I do use a PC (two different machines during these attempts) and always format to Fat32.  In fact, I found that if the flash drive is not formatted to Fat32, Jeppesen won't transfer the data.  In one attempt I simply formatted as FAT (which turns out to be Fat16) and Jeppesen couldn't 'see' the device.

As for the large file, I think you're talking about the terrain database.  My understanding is that it was pulled because they found it was the same database initially installed in all the units.  A new one is supposed to be coming out soon.  For now I was just doing a normal chart update ... or trying to.

Which IFD540 software version are you on?  I'm not sure if there have been improvements made to to the data update process, but for sure there were issues with v10.0.3.  

ddgates - I did that, too.  With Jeppesen on the phone I worked through the variety of issues they could imagine on their end.  I even changed from the older JSUM download system to the new-and-improved JDM; still no success.

Lance - No I did not connect to external power.  I don't have a ready source, but it only takes a couple of minutes to update the charts.