If you are having issues with your Powerbook waking up at the wrong time (in your backpack for instance) because the lid latch is weak, then run the following command from a concole window:

sudo pmset lidwake 0


The man page for this is:
http://developer.apple.com/documentation/Darwin/Reference/ManPages/man1/pmset.1.html

PMSET(1)                  BSD General Commands Manual                 PMSET(1)

NAME
     pmset -- modify power management settings

SYNOPSIS
     pmset [-a | -b | -c | -u] [displaysleep minutes] [disksleep minutes]
           [sleep minutes] [womp 1/0] [ring 1/0] [autorestart 1/0] [dps 1/0]
           [reduce 1/0] [powerbutton 1/0] [lidwake 1/0] [acwake 1/0]
           [lessbright 1/0] [halfdim 1/0] [sms 1/0] [boot]
     pmset -u [haltlevel percent] [haltafter minutes] [haltremain minutes]
     pmset -g [disk | live | cap | sched | ups | ps | pslog]
     pmset schedule [cancel] type date+time [owner]
     pmset repeat cancel
     pmset repeat type weekdays time

DESCRIPTION
     pmset changes and reads power management settings such as idle sleep tim-timing,
     ing, wake on administrative access, automatic restart on power loss, etc.

SETTING
     The -a, -b, -c, -u flags determine whether the settings apply to battery
     (-b), charger (wall power) (-c), UPS (-u) or all (-a).

     Use a minutes argument of 0 to set the idle time to never.

     pmset must be run as root.

     The boot argument tells power management that system bootup is complete.
     Loginwindow handles this on a normal Mac OS X system.

GETTING
     The -g flag outputs the settings currently in use (same as -g live ).
     -g disk will display settings on disk.
     -g cap will display which power management features the machine supports.
     -g sched will display scheduled startup/wake and shutdown/sleep events.
     -g ups will display UPS emergency thresholds.
     -g ps will display status of batteries and UPSs.
     -g pslog will display an ongoing log of power source state.

ARGUMENTS
     displaysleep - display sleep timer; replaces 'dim' argument in 10.4
     (value in minutes)
     disksleep - disk spindown timer; replaces 'spindown' argument in 10.4
     (value in minutes)
     sleep - system sleep timer (value in minutes)
     womp - wake on ethernet magic packet (value = 0/1)
     ring - wake on modem ring (value = 0/1)
     autorestart - automatic restart on power loss (value = 0/1)
     dps - dynamically change processor speed based on load (value = 0/1)
     reduce - reduce processor speed (value = 0/1)
     powerbutton - sleep the machine when power button is pressed (value =
     0/1)
     lidwake - wake the machine when the laptop lid(or clamshell) is opened
     (value = 0/1)
     acwake - wake the machine when power source (AC/battery) is changed
     (value = 0/1)
     lessbright - slightly turn down display brightness when switching to this
     power source (value = 0/1)
     halfdim - display sleep will use an intermediate half-brightness state
     between full brightness and fully off  (value = 0/1)
     sms - use Sudden Motion Sensor to park disk heads on sudden changes in G
     force (value = 0/1)

UPS SPECIFIC ARGUMENTS
     UPS-specific arguments are only valid following the -u option. UPS set-settings
     tings also have an on/off value. Use a -1 argument instead of percent or
     minutes to turn any of these settings off. If multiple halt conditions
     are specified, the system will halt on the first condition that occurs in
     a low power situation.

     haltlevel - when draining UPS battery, battery level at which to trigger
     an emergency shutdown (value in %)
     haltafter - when draining UPS battery, trigger emergency shutdown after
     this long running on UPS power (value in minutes)
     haltremain - when draining UPS battery, trigger emergency shutdown when
     this much time remaining on UPS power is estimated (value in minutes)

SCHEDULED EVENT ARGUMENTS
     pmset allows you to schedule system sleep, shutdown, wakeup and/or power
     on. "schedule" is for setting up one-time power events, and "repeat" is
     for setting up daily/weekly power on and power off events. Note that you
     may only have one pair of repeating events scheduled - a "power on" event
     and a "power off" event.

     type - one of sleep, wake, poweron, shutdown, wakeorpoweron
     date/time - MM/dd/yy HH:mm:ss (in 24 hour format)
     time - HH:mm:ss
     weekdays - a subset of MTWRFSU ("M" and "MTWRF" are valid strings)
     owner - a string describing the person or program who is scheduling this
     one-time power event (optional)

OTHER ARGUMENTS
     boot - tell the kernel that system boot is complete (normally LoginWindow
     does this). May be useful to Darwin users.
     force - tells PM to immediately activate these settings. Does not write
     them to disk, and the settings may easily be overwritten. Useful in cir-circumstances
     cumstances where PM's configd plugin happens not to be running.
     dim - deprecated in 10.4 in favor of 'displaysleep'. 'dim' will continue
     to work.
     spindown - deprecated in 10.4 in favor of 'disksleep'. 'spindown' will
     continue to work.

EXAMPLES
     pmset -b displaysleep 5

     pmset -a displaysleep 10 disksleep 10 sleep 30 womp 1

     pmset -u haltlevel 40

     pmset -g

     pmset -g batt

Files
     All changes made through pmset are saved in a persistent preferences file
     (per-system, not per-user) at
     /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist

     Scheduled power on/off events are stored separately in
     /Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist

     pmset modifies the same file that System Preferences Energy Saver modi-modifies.
     fies.

Darwin                          August 19, 2002                         Darwin