My 32GB SD card (FAT32) does not have any problem mounting perfectly if my laptop (running Ubuntu 14.04) never goes into suspend (after I close its lid).
But once I re-open the lid, retyping my password to login and resume working as before, the SD card vanishes, as if nothing was ever mounted... Pulling it out then re-inserting it doen't resolve the problem. I have to power of my laptop completely before the card is recognized and mounted again.
I have Windows 8.1 running on the same laptop (Lenovo Y50-70, dual-boot) and it has no such problem whatsoever, so this is unlikely to be a hardware problem. This points towards more like a driver bug in Ubuntu 14.04.
Is this a known issue? If so, do you know of any way to workaround it? (short of the aforementioned power-off)