My husband's stellar has the same issue. I went and bought an sd card for his phone because he had
VERY little memory after basic stuff. But NO WAY to transfer anything there...apps or music...despite it clearly showing as in there with EMPTY memory.
What is the deal with this phone/?????
As noted in another thread (Re: How do I move apps to my SD card on a Galaxy Stellar?) you won't be able to move apps to the SD card due to the OS, but you should be able to move photos/music/documents to the SD card using a file manager. If the phone didn't come with a file manager, you can download one from the Play Store.