I managed to unlocked the boot loader and rooted. I installed Link2sd with Ext2 formatted second partition. I link all my application from internal memory to sd card. Everything is working fine, but after 15 minutes my sd card removed unexpectedly. Then I reboot phone and create the mount script partition again. After some time the SD card removed again. All my apps including updated play store, keyboard, face book, Titanium Backup etc all get removed. Earlier I use the same SD card in Moto Defy XT 535 for last two years and no problem acquired. Now I reset my phone to factory and re installed all apps again, It working without any problem. Any one know which format is suitable and working without any problem?