I have been running 2.5.1 and kernel 2.0 for a while now. No Reboots or bootloops. I run Cpu Adjuster and am Undervolted. I have had to up my voltages slightly to make it more stable. I run Pegasusq and Deadline when the phone is in use with the second core set to auto, and pegasusq and SIO when the screen is off or in a call with the second core OFF. Could the bootloops be cause by the default scheduler?