Does it reboot on a stock ROM?
Are you running stock performance settings? Have you tried wiping cache and dalvik?
I tried flashing multiple ROMS and it still happens. I'm thinking it may be a power button issue, I just set my home button to wake the phone and set the screen to time out quicker then usual is my only fix.
If it is not home button issue and if you have reboots with only custom roms, you should try to check kernel voltages using trickster mod app. Too low or too high voltages may cause reboots.