HTC thought it best to cover their own ass by placing a red warning whenever you start your device if you've unlocked your bootloader. While it may help them identify a tampered phone, it does not help you in any way. Luckily, XDA member santod040 created a modified HBOOT that removes the "This build is for development purposes only..." text for you. While this will modify HBOOT, it will not change your unlocked or S-Off status.
The new HBOOT will be flashed in RUU mode, which is like a special recovery mode that can only be accessed through fastboot. You should keep in mind that the HBOOT... more