I believe that the external SD card (micro SD) is treated like a media storage. By design, the phone will only transfer media files (photos, music, documents, etc.) using the File App. You can always use a 3rd party app if you wish to transfer anything else. The internal SD card is used as the main "storage" for files. Apps are installed to the internal memory (non-SD card) and can be moved to the internal SD card using either a 3rd party app (Apps2SD, etc.) or natively (Settings/Applications/Manage Application and choose "Move to media area"). The "Media area" is the internal SD card. Apps do not install/move to the external SD card. Hope that this helps.