975X Platinum PowerUp - Windows will not Restart - only shutdown

Question

I've had a MSI 975x Platinum Powerup for several weeks now and have a really annoying problem.
When booted and in Windows the system is pretty stable. I've even had some success at overclocking (up to 333 with an E6400). However, even when not overclocked it I select Windows Restart the machine will shutdown but will not POST on the restart. The machine just sits there with no video signal.
however if I do Windows Shutdown and the physically power the machine back on, everything seems okay.
This maybe isnt a big deal, but is very irritating. I've seen some passing reference to other members of the forums that have a similar sounding problem, but there are no details.
Could anyone tell me if this is a known issue, and whether there is a solution or not.
Is it the case that only some people have this problem or do all 975x users have it?
I've tried MSI support who just responded with a generic 'have you checked x,y,z' message.
have detailed some of the other components of my machine below - let me know if you need anything more
Thanks in advance,
James.
BIOS: 7.3 (7.1 and 7.2 had the same problem also)
VGA Type:MSI GeForce 7900 GTO SILENT 512MB
CPU Type:E6400
Memory Type:GeIL 2GB (2x1GB) PC6400 800MHz Ultra Low Latency DDR2 Dual Channel Kit
Power Supply Type:650W XCLIO X14 PSU
Operating System:Windows XP professional

Answer 1

Hi, The only thing I need to change in the bios is to turn off 'spread spectrum' and run the memory @2.2v. I have found turning off speedstep and C1E made no difference for me. At 375 if you run the memory with the 1:1 divider it will be running @750 so you can manually select 4,4,4,12 for the memory timings. This will not help the restart problem though.
Having said that, any bios after 7.2 will alter your manual memory settings and if you enter the above ( GeILs recommended settings) it will change them to 4,5,6,12.......... Another bios quirk I'm afraid!
To get around this you can go back to bios 7.1 which leaves these settings alone. What I have found works well is to leave the divider option on 'AUTO' . This applies the 1:1.25 ratio, and leaves memory timings on 4,4,4,12 with the ram running @875 when on 350 FSB. I run this setting @ 375, but I put the memory timings on 'SPD' as the ram is then running @938. You can run up to 2.3v through this ram according to OCUK where I bought the memory which may help you get up to these speeds or tighten the timings a bit.
380 is about the fastsest mine will boot at and adding more vcore (up to 1.4v) made no difference to this. I have tried upping the pcie voltage (which is the chipset voltage on this board) to 1.6v, but this didn't help either! Some people seem to get over 400FSB easily and others seem to have hit the same wall as me. People who can attain the high FSB speeds don't seem to suffer from the restart problems either! WEIRD!!
Let us know how how you get on.