E6400 in sleep mode (either via Windows or by closing the lid) will start back within 1-3 minutes. Had the problem occasionally since new but started within 1-3 minut interval after first use in docking station. It will do it regardless of any program on/off.
running XP SP3.
found the problem - go to "my computer" "properties" "hardware" "device manager" and in "network adapters" DISABLE in "power management" function "WAKE UP ON LAN". All of them..... Do not forget to do same on wireless adapter.
this took care of the issue on my 6400.
This did not correct the issue. I came accross: http://windows.microsoft.com/en-US/Windows7/Sleep-and-hibernation-frequently-asked-questions.
Programs can also wake the computer apparently, in addition to hardware. I disabled that ablity as well. Will find out tonight if it works.