Let's see break it down briefly:
OC'ing the proc to 3.2ghz is considered a moderate OC'ing for the E7300, that wouldn't do significant damage, the failure to P.O.S.T due to not enough Vcore to the E7300, commonly.. so that rules it out atm...
The Ram, its hard to tell bcoz I believe in this situation, the problem might not be the RAM, but the whole system configuration and the most apparent culprit atm is an un-updated BIOS, because I believe it "thinks" that a 4:5 divider is more stable than a 1:2.

The only way to narrow it down is if you could borrow another ram (800mhz) to see if the prob occurs, IF the 'halt' still occurs, then you at least have an idea where the problem comes from...the BIOS..
After you update the BIOS, there's still one more step, to see if the system stable after updating.
IF the 'halt' still occurs, then its the mobo, thats the only deduction that can be drawn from this troubleshoot...roughly. 

Another thing not to be overlooked: The PSU.
Sometimes its just the PSU who's causing the menace, but it always slip people's minds because the PSU always comes across as the 'unusual suspect' from the distraction of toubleshooting the other things.(mobo,bios, ram, etc.)So if you can get your hands on another PSU atm, you should give it a try to narrow down the problem.
For testing, a fresh cap ayam PSU can be used, but just temporarily for testing only.

OK bro, thats most of the troubleshoots you can DIY for now.

I hope you can do most of the suggested troubleshooting, which is enough to figure out the main villain, or villains.
It's worth it  to do all things boring and tedious procedures, because it will get you closer to finding out what's up 
@farscope,
I'm still thinking what's going on with your situation atm, I wont say anything yet until I'm sure with the comments prior to you post. 

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Added on December 28, 2009, 2:50 am
Sometimes with a 1066mhz ram, with default settings usually it sets the ram to 800mhz, so need to manually set the ram clockspeed to 1066mhz...

It's just the bios...probably needs flashing...but can't tell yet...

I c, I never owned a Gigabybte board.. I only know much of the Asus mobos.
I lik Asus bios settings(specifically 'Ai Tweaker'), it's very nice to OC, especially to do with this PL thingy.

The PL thing you need some time of research hours, dunno what it's called in Giga boards, but for now should un~leash the potential of that HyperX 1066mhz.

Now that you mastered CPU overclocking, you should move to RAM OC'ing.
In RAM OC'ing, either tighten the ram timing or increase the clock speed while tweaking the voltage(vDimm) for stability.
(I dunno if the HyperX can do both tight timing and high clocks at the same time...at least stabilization is concerned.)
Then run prime95 or any proper memory stress test software to test the ram out.   
After that, you need a memory benchmark test, e.g. 'Everest memory test & benchmark' to compare which configuration is best.

Sound complicated? Not really, just need time grasp the idea.
Even a guy like me who takes these thing as one of my many hobbies took less than 6 months to learn adequately to OC the PC..
Your HyperX is crying to be OC'ed, even a little is good enough... 

Btw, I like that Old Town Hazelnut Coffee   

Clocks are the mhz, 5-5-5-15 is timing.

One of the criteria of a good OC'ing result are those with the lowest stable Vcore possible for 24/7 usage -  so to get the Vcore lower than 1.38v is benefiting the longevity of the proc.

Since you have a Giga board, the PL (which usually the term use on Asus boards) are in this case, tRD.

First, find the default value of your board's tRD (meaning change the setting from AUTO to manual) then lower it in increments while testing for stability with prime95 and performance with Everest ->' Cache and Memory Benchmark' (it's a freeware software, just download it)
Since this is no longer a proc OC'ing, you should ask other sifus on other related thread...

Yup, try to find the 'lowest stable Vcore' for your proc.
Anything above Intel's maximum recommendation of 1.3625v is taking it's toll on the 45nm procs..

Btw, your P43 chipset mobo is good for OC'ing, those Asus Maximus Formula's, Rampage, Bigbands, etc. are just rich man's toys, any P45 or at least P43 chipset mobo can OC decently, just that the P45's are known to edge the P43 a bit..
But that's not something to be that concern about, for OC'ing stability, it's the hardware itself, mostly the mobo....for instance the 'power phase design' (those dark box like capacitors that surrounds the 775 socket) are more important for reliability of 24/7 duty and will endure longer OC abuse...

Having said, no need to upgrade to P45 for the sake of this, you better off using your current giga board till it breaks down in years and allocate the budget for the upgrade of socket 1156 (i3, i5, i7 860) in the future... 

EDIT:
Just read back the pages and realize you have a 4G HyperX DDR2 1066mhz RAM, right?

Keep the clocks(mhz) stock or OC the clocks over 1066mhz, if you can get your RAM to OC near 1200 (if your mobo supports up to that frequency) your enhance the overall system performance!
That HyperX is meant to be OC 

That '1:1 ratio' is just a primary goal for any one who tries to OC their proc, there's a whole new world of OC'ing if you past that '1:1 ratio' point...overall system performance plays a bigger role get your PC at peak performance.
Do download Everest to see the performance increase when tighening up the tRD or OC'ing the RAMs...