While we don't have a lot of these coming in, we do have one report from a reader of having severe issues on their Focus after installing an "approved" 32GB card from Sandisk.
I have a Focus with a Sandisk 32 gig micro sd card which Sandisk said was approved by them. Well today it crashed (reset and wiped all info & apps off the device). It looks like the card is fried - only show 85 meg. What should I do ? (About the phone and the card)
In a situation like this, the only real solution is to remove the card and hard reset the device through Settings. If the device is unable to factory reset through the software i.e. the phone is unbootable, then you need to use the hardware buttons to do the factory hard reset:
1. Press and hold the Camera, Volume Down, and Power buttons simultaneously.
2. Release Power when the phone vibrates, but continue to hold down Camera and Volume Down.
3. Release Camera and Volume Down when the Format prompt is displayed on screen.
4. Press .
5. Press again to confirm the hard reset.
Regarding the microSD card, outside of trying to reformat it with a Nokia N8 (seriously, that's the only known method), we're not sure what to suggest besides trying to return/exchange the card with Sandisk (assuming you bought through them). You could also try to factory reset the phone, put in the card and see if it can reformat it that way, though we're not hopeful.
Update: Reader Elan S is having the same issue with a Sandisk-approved 16GB Class 2 card.
Read the Samsung FAQ on SD cards for the Focus here. Thanks Paul for the question and let us know how you proceed! Anyone have a better answer? Tell us in comments.