On my Mac Mini, the hardware clock was seriously screwed up under Debian. The clock would set itself 1 hour back for each boot and cause all kinds of strange issues with cron when corrected. A small fix will remedy this situation.

1. sudo vim /etc/init.d/hwclock.sh

2. change ‘HWCLOCKPARS=’ to ‘HWCLOCKPARS=”–directisa”‘ (note: that’s two dashes before directisa, even if your browser might put them together)

3. On Debian Lenny, you have to do the same to the HWCLOCKPARS line in /etc/init.d/hwclockfirst.sh