It seems other people are experiencing the same thing. Unfortunately, that guy didn’t get a response. Both of these readings were taken with no Xorg or Wifi running. The laptop is a Pentium M Centrino model.
kernel 2.6.22-hrt6

PowerTOP 1.8 (C) 2007 Intel Corporation
Collecting data for 15 seconds
Cn Avg residency
C0 (cpu running) ( 0.1%)
C1 0.0ms ( 0.0%)
C2 60.5ms ( 4.9%)
C3 0.0ms ( 0.0%)
C4 645.0ms (95.0%)
P-states (frequencies)
1.87 Ghz 0.0%
1.60 Ghz 0.0%
1333 Mhz 0.0%
800 Mhz 100.0%
Wakeups-from-idle per second : 2.3 interval: 15.0s
no ACPI power usage estimate available
Top causes for wakeups:
40.4% ( 1.5) laptop_mode : queue_delayed_work_on (delayed_work_timer_fn)
12.3% ( 0.5) <interrupt> : ide0
12.3% ( 0.5) <kernel> : queue_delayed_work_on (delayed_work_timer_fn)
7.0% ( 0.3) <kernel> : neigh_table_init_no_netlink (neigh_periodic_timer)
5.3% ( 0.2) ifplugd : schedule_timeout (process_timeout)
5.3% ( 0.2) <kernel> : page_writeback_init (wb_timer_fn)
5.3% ( 0.2) init : schedule_timeout (process_timeout)
3.5% ( 0.1) cupsd : schedule_timeout (process_timeout)
1.8% ( 0.1) <kernel> : end_that_request_last (laptop_timer_fn)
1.8% ( 0.1) <kernel> : init_nonfatal_mce_checker (delayed_work_timer_fn)
1.8% ( 0.1) cifsdnotifyd : schedule_timeout (process_timeout)
1.8% ( 0.1) <kernel> : seqgen_init (delayed_work_timer_fn)
1.8% ( 0.1) <kernel> : init_sunrpc (delayed_work_timer_fn)

Kernel 2.6.23-rc4-hrt1