Hi, I'm having this same exact problem. In fact, my phone isn't getting stuck at the boot screen, per se. Rather, the motorola logo just gets stuck on the screen. After a minute or so, if I slide my finger in the right place, I can act like I'm unlocking my phone, even though I can't see what I'm doing.
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Also, I've noticed that when this happens and I'm able to turn the phone off, the moto logo appears to be somewhat burned into the screen, kind of like what could happen with the original plasma televisions if a still image was displayed on it too long. It's only slightly noticeable, though. Oddly enough, if the phone boots up correctly and I then quickly press the power button to turn off the screen, the screen is completely blank and there's no "burned in" image (the same thing happens if I pull the battery out - there's no faint ghost image on the screen).