Got the phone 4 months ago. I love it, but wanted more memory for music - so I bought a 2 GB Sony High Speed Memory Stick Pro Duo. After loading music on it the phone would play the music for about 2-3 minutes and then it would give me a "Playback Failed" error message. I tried everything (reformat memory, reformat phone, using the MP3 software, NOT using the MP3 software, etc.) yet nothing would work. I did find a similar case online where the user then bought a SanDisk Pro Duo memory stick which then worked for him. Sure enough, I ordered a 4 GB SanDisk Pro Duo card and the phone works great. Just a heads up to everyone looking to upgrade their memory.