MacOS – MacBook Pro won’t sleep automatically — no process preventing sleep according to pmset. What’s going on

i noticed the following problem with my MBP 8,1 running 10.7.2 — automatic sleep just doesn’t happen. Since I usually put my Macbook to sleep manually before leaving the desk etc. I just noticed this issue and can’t really pinpoint it to specific updates.

What happens automatically is display sleep. Computer sleep just doesn’t occur.

Closing the lid works, selecting “sleep” from the Apple menu works. The only way to put my MBP to sleep automatically is currently PleaseSleep, which works fine.

Here’s pmset -g:

pmset -g 
Active Profiles:
Battery Power       1
AC Power        -1*
Currently in use:
 standbydelay   4200
 standby    0
 womp       1
 halfdim    1
 panicrestart   157680000
 hibernatefile  /var/vm/sleepimage
 sms        1
 networkoversleep   0
 disksleep  10
 sleep      10
 hibernatemode  3
 ttyskeepawake  1
 displaysleep   3
 acwake     0
 lidwake    1

As you can see, no process is preventing sleep.

Here’s pmset -g assertions:

pmset -g assertions
25.12.11 03:05:34 MEZ   
Assertion status system-wide:
   ChargeInhibit                           0
   PreventUserIdleDisplaySleep             0
   PreventUserIdleSystemSleep              0
   NoRealPowerSources_debug                0
   CPUBoundAssertion                       0
   EnableIdleSleep                         1
   PreventSystemSleep                      0
   DisableInflow                           0
   DisableLowPowerBatteryWarnings          0
   ExternalMedia                           0

Kernel Assertions: 0x0004 
 * Kernel Assertion ID = 500
   Created At = 01.01.70 01:03:17 MEZ   
   Modified At = 25.12.11 02:46:14 MEZ   
   Owner ID = 0xffffff800b664000
   Level = 255
   Assertions Set = None (4)

 * Kernel Assertion ID = 501
   Created At = 01.01.70 01:03:21 MEZ   
   Modified At = 01.01.70 01:00:00 MEZ   
   Owner ID = 0xffffff800b674000
   Level = 0
   Assertions Set = None (4)

 * Kernel Assertion ID = 502
   Created At = 01.01.70 01:05:31 MEZ   
   Modified At = 25.12.11 02:38:13 MEZ   
   Owner ID = 0xffffff800b704200
   Level = 0
   Assertions Set = None (32)

Any ideas? I tried resetting the SMC, to no avail.

Bluetooth is off, Sharing is off. Automatic sleep doesn’t occur both on power adapter and battery power. Unplugging USB hub with things like keyboard/mouse connected makes no difference.

Thanks in advance!

EDIT Just booted into safe mode, and automatic sleep definitely works then.

EDIT 2 After removing Google Software Update, automatic sleep miraculously started working again.