You don't need R&D to get root access. Just install rootsh. But what do you mean your permissions changed? How did you find out?

The most likely cause is a file system corruption. The OS then mounts the volume as read only, giving only root the write access. Since MyDocs is FAT, the usual remedy is attaching it to a Windows PC in Mass Storage mode and running a disk check on the PC. You could try fsck on the phone but that is less likely to guarantee a success. In some cases it may make the situation worse.