Android keep saying "SD Card is mounted, do you want to change your default storage"

About two days ago, I received this notification. At first, I just click on "Change",and in setup, set default storage to SD Card. I'm using Android 4.2.2. But, this is happening in every half hour... I rooted my phone about 2 mounts ago,installed link2sd,and created second partition on my 16Gb SD Card. Both partitions are marked as Primary and both are FAT32. It's worked very well until 2 days ago. When I receive notification about SD Storage, my whole second partition stop working. Every apps on second partition is "unreachable" and I must restart my phone. Do you know how to "fix" this, because, my SD Card is ok,it's seems that android unmount and mount SD Card and show this notification automaticly. EDIT: I forgot to mention, when I format whole SD Card,and delete second partition, this notification is not showing,but,again,when I create second partition, notification is shown on my home screen,and keep asking me to change default storage.