I have a galaxy S3 with a 32gb class10 sd card.
Unfortunately I experience the SD card unexpectedly removed - Preparing SD card phenomenon all the time. The card works ok as long as it is being used: I watch videos, mp3 etc, even on pc.
I tried formatting a couple of times and I also checked on other S3 phone which presented the same problem. I checked a 16 GB class 10 card on my phone which worked ok!
I read somewhere that this is a JB problem and that I should wait for 4.2 (I'm on 4.1.1 now)
Another solution explained that I should root my phone and do this:
Edit files in the folder /sys/devices/virtual/bd i/179: 0/read_ahead_kb by pressing and holding the read_ahead_kb then choose open in text editor.
Note: Other phones don't have 179:0.. but is ok 179:8 Replace the numbers in it from the default (128KB) to 1024 / 2048 / 4096 (according to taste max = 4096) and then save and exit.
What are your thoughts? is it JB or the Card?
I should also mention that the removing/rescanning my card is killing my battery very fast.