Since a couple of days I have a very weird problem with the following config:
Asus P5K-E/WIFI-AP
Corsair TWIN2X2048-6400, 2x1GB, DDR2-800
Intel Core 2 Duo E6750, Dual Core, 2.66 GHz
Asus EN8600GT SILENT/2DHT/256M
Corsair CMPSU-520HXEU, 520W
Samsung SP2504C, P120S, 7200rpm
 
At the very first "morning" startup, the pc does not want to boot, the hdd led does not show up.  
No display.
Reset an retry will not help.  
 
However, if I switch off manually the Power Supply, wait a little, re-start then it boots complaining about "overclocking failed".
I enter the boot setup, do no modification, save and exit, no problem at all!
 
ps: when it manages to boot, i observe that it does it in 2 times: I see my akasa fan controller showing up, then suddenly off during one second and eventually starts up. I don't remember such a behavior before.
 
Is this possible there's a defect on the MB?  
Many thanx and sorry for my so-called english.  
 
CPU-Z 1.41 report file
Processor(s)  
Number of processors 1
Number of cores 2 per processor
Number of threads 2 (max 2) per processor
Name Intel Core 2 Duo E6750
Code Name Conroe
Specification Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz
Package Socket 775 LGA
Family/Model/Stepping 6.F.B
Extended Family/Model 6.F
Core Stepping G0
Technology 65 nm
Core Speed 3199.7 MHz
Multiplier x Bus speed 8.0 x 400.0 MHz
Rated Bus speed 1599.9 MHz
Stock frequency 2666 MHz
Instruction sets MMX, SSE, SSE2, SSE3, SSSE3, EM64T
L1 Data cache (per processor) 2 x 32 KBytes, 8-way set associative, 64-byte line size
L1 Instruction cache (per processor) 2 x 32 KBytes, 8-way set associative, 64-byte line size
L2 cache (per processor) 4096 KBytes, 16-way set associative, 64-byte line size
Chipset & Memory  
Northbridge Intel P35/G33/G31 rev. A2
Southbridge Intel 82801IR (ICH9R) rev. 02
Graphic Interface PCI-Express
PCI-E Link Width x16
PCI-E Max Link Width x16
Memory Type DDR2
Memory Size 2048 MBytes
Memory Frequency 400.0 MHz (1:1)
CAS# Latency (tCL) 5.0 clocks
RAS# to CAS# (tRCD) 5 clocks
RAS# Precharge (tRP) 5 clocks
Cycle Time (tRAS) 15 clocks
Command Rate (CR) 2T
System  
System Manufacturer System manufacturer
System Name P5K-E
System S/N System Serial Number
Mainboard Vendor ASUSTeK Computer INC.
Mainboard Model P5K-E
BIOS Vendor American Megatrends Inc.
BIOS Version 0806
BIOS Date 10/31/2007
Memory SPD  
Module 1 DDR2, PC2-6400 (400 MHz), 1024 MBytes, Corsair
Module 2 DDR2, PC2-6400 (400 MHz), 1024 MBytes, Corsair
Software  
Windows Version Microsoft Windows Vista (6.0) Business Edition (Build 6000)
DirectX Version 10.0

i have similar simptoms with my Asus P5E Mb and i can asure u that its a bios problem.. at least in my case is... although in my case it does that randomly .. on some restarts it boots on some it doesnt.. reagardless of the hours spent running till that moment. Anyway it might be a power supply issue but i highly doubt.. i suppose that just like in my case if it does boot succesfully then it runs without errors... if i switch to previous bioses the problem dissapears... but it doesnt bother me that much
 
did u do a recent bios upgrade?  

yes indeed, i did a last update of my bios (0806).  
i wonder whether it can be a problem with the core voltage@3200 or something like that...  
 
and what i do not get is the strange startup in 2 steps.

it is a well known issue so you are not alone. I have the exact same board but have not had this issue yet. I am still running on 0606 and plan to stay that way and hope nothing goes tits up.
 
There was another thread i saw yesterday regarding this exact same problem. Hunt around.

, too, have had a similar problems involving an ASUS P5K-E motherboard, since its purchase.   The system will not automatically recover from sleep states, whether S1 or S3.   I also cannot reliably get an automatic reboot when I perform a Shutdown/Restart of the system.  I first thought this is because I have Windows XP 64 bit installed.  I have tried a myriad of bios settings, and I have tried several measure measures of troubleshooting that could be linked to XP 65 bit/Visa, but to no avail.  When the problem happens,  the only way I can recover the system is to completely power down the system from the wall plug.  I have talked to ASUS technical staff twice about this issue, and they seem oblivious.   What should I do?

[#71008d]I Have the P5K-E WiFi AP version of this board...   and it has alway's started in 2 step's also ?
 
Press the power button - everything start's....   then it all dies for 2 second's or so...    then start's up again and boot's into Vista..    Strange, i have'nt a clue if it's a fault or just the way this board start's up !
 
Spec :-
 
Vista 32bit
P5K-E WiFi AP (Bios 1013)
2 x 1GB OCZ Spec Ops
Core 2 Duo E8500  (not clocked)
Tagan BZ Piperock Series 600w Modular PSU
GeForce 8800GTS 640mb (Leadtek)
 
Gen-x.