I'm using Transcend Micro SD Card. When I try to copy some files from my system(12.04), it's getting write protected and also unmounting the device. I'm unable to copy files to it.
In case, if you are using Sandisk, please do the following (If the lock switch is not on lock):
- Slide the switch up and down. Repeat this 3 times.
- Let it stay on the Lock position for 30 seconds.
- Slide the switch up to unlock the card.
- Try to transfer files into the device.
Yes it is strange and yes it works, as per this source.