With the Bluetooth patch active, use RemindMe to auto-sync your phone with a PC over OBEX. It turns your 6600 into a Bluetooth remote for Windows Media Player.
This frustrated a generation of budding power users. They wanted to: Nokia-6600-apps-s60v2-rompatcher
Fix: Your firmware is too new (e.g., v5.27). The 6600 requires a "patcher-friendly" firmware. Downgrade using a USB flasher (JAF box) or find a pre-patched firmware flash file. With the Bluetooth patch active, use RemindMe to