Firefox setttings won't transfer via simple copying of portable app folder.

Running Firefox Portable from the SD mico card in my Windows 8 tablet, I found that all my settings had gone. No bookmarks and no plugins. So I plugging in my USB memory stick backup to make a fresh copy of the entire Firefox Portable folder (having deleted the old one) on the SD mico card. But still no bookmarks or other saved settings. Firefox Portable runs perfectly from the USB stick, and runs perfectly from every other drive and USB stick I have spent the last hour copying it to. But it will not copy or run correctly from this one SD mico card that I am using in my tablet. I even tried transferring via a zipped folder. Then did that again using 7-Zip. But always the same. Looking in the folders on the SD card, all the profile folders and files are there. Absolute mystery. I am running Firefox from a different folder on the tablet's c drive, which means I can't start it via the Portable Apps interface.