MacBook doesn't go into standby mode as it should?

Question

I recently set the standby delay on my MacBook to 600 (seconds) thinking that would cause it to go into standby/hibernation after 10 minutes of sleep. However, when I open the lid after several hours of sleep, I find that the "lag time" before I can enter my password that I have previously noted and interpreted as a sign of the system coming out of standby is not there. Also, when i use "pmset -g log" to view the power logs, there's no indication that the system goes into standby mode after the set standby delay. Here is an excerpt from the logs:
4/8/14 1:34:29 AM GMT+02 Sleep             
Clamshell Sleep Sleep: Using BATT (Charge:88%)                           
29298 secs
4/8/14 1:34:29 AM GMT+02 Assertions         
PID 73(apsd) Released ApplePushServiceTask "com.apple.apsd-waitingformessages-sandbox.push.apple.com" 01:15:02  id:0xc00000c75 Aggregate:0x402040
4/8/14 1:34:29 AM GMT+02 Assertions         
PID 73(apsd) Released ApplePushServiceTask "com.apple.apsd-waitingformessages-push.apple.com" 00:10:50  id:0xc00000d15 Aggregate:0x402040
4/8/14 1:34:29 AM GMT+02 WakeRequests       
Clients requested wake events: None                                       
4/8/14 9:42:47 AM GMT+02 Wake               
Wake due to EC.LidOpen/Lid Open: Using BATT (Charge:82%)                 
617 secs 
4/8/14 9:42:47 AM GMT+02 HibernateStats     
hibmode=3 standbydelay=600                                               
rd=336 ms
Shouldn't there be a log entry somewhere around 1:44:29 (i.e. after 600 seconds of sleep) indicating that the system is going into standby? As can be seen from the log, the battery drops from 88% to 82% during this 8 hour period. As far as I can understand, standby mode is equivalent to Windows "hibernation", where the contents of the RAM is stored on the drive, meaning the computer uses no power during standby. So why isn't standbydelay 600 working as I expect it to?

Answer 1

Update: Uninstalling Avast didn't seem to help. I've also set "autopoweroffdelay" to 600 and "autopoweroff" to 1, no effect. I closed the lid 7 hours ago, computer was still in sleep mode when I opened the lid (nothing connected to it)
So far, setting "hibernatemode" to 25 is the only thing that actually puts my computer into standby/hibernation, although it does that straightaway. I've set hibernatemode 3 for AC power and hibernate mode 25 for battery.
So much for Macs' "just working", the guy who came up with that clearly never owned a Mac... at least not for some time.