Logomatic V2 (LPC2138) power control problems

I would like to reduce energy consumption of Logomatic V2 board.

In power-down mode despite the LPC2138 manual the internal clock is still working for about 2-3 days. Unfortunatelly the clock stops then and that means big delay after waking up via external interrupt. Unfortunatelly the RTC alarm and the watchdog functions are not working from power-down. I can not see other solution for keeping date and time when waking up from power-down mode.

In idle-mode I failed to use external interrupt for wake-up, however the same method should have worked as in case of power-down mode. (program code attached) In addition the energy consumption is higher then in power-down mode.

So anybody succeed to use power-down mode and keeping the time of internal clock ?

thanks