My 2ds keeps saying my SD card is write protected but its not

[Slysword]

I keep flipping the switch but its still not working. Ive tried cleaning the sd card slot but nothing happened. This is my fourth sd card. What do i do?

 

[cin19]

Try those from the link http://www.steves-digicams.com/knowledge-center/how-tos/photo-accessories/fixing-the-memory-card-write-protected-error.html