Reset after Sleep

Hello all, I have an interesting issue with my LPC1768 design.  I am using the CMSIS libs and the CTL RTOS

I have tasks running via timer IRQ events all the time, and very infrequent user external IRQ events.  To save power when no active task is running, I put the processor to sleep by calling CLKPWR_Sleep() from main (the idle task). If the user has not done anything after a while I will set an event to put the processor into deep sleep.  From deep sleep it wakes up via an external IRQ.  Part of that ISR sets an event that causes the my board init to run.  All works good, until the end of my board init routine and the board enters sleep mode as it has become idle again.  When that happen the system reboots.  Let me say that my board init routine pretty much does everything so all the devices are working as they should, but somehow re-entering sleep mode after deep sleep creates the reset.  BTW it works the same for booth deep sleep and power down