Memtest Errors. Sometimes passes with 2 RAM sticks but fails with 4?

[geokilla]

Specifications:
AMD Phenom II X3 720, unlocked to 940 BE @ 3.1GHz
Gigabyte GA-MA785G-UD3H
Mushkin Redline 2X2GB PC2-8000 5-5-5-12 @ 2.0V to 2.1V (already RMA'd once)
Patriot PDC22G6400LLK - DDR2 800MHz 4-4-4-12 @ 2.2V
Crucial M4 120GB SSD from at least 6 or 7 years ago (current running at SATA 1.5G speeds?!)
OCZ StealthXStream 500W
Nooctua NH-U12P

Current BIOS Settings:
CPU clock Ratio @ 3100MHz
CPU Northbridge Frequency @ 2000MHz
CPU Frequency @ 200MHz
PCI-E @ 100MHz
HT Link Width @ 16 bit
HT Link Frequency @ 2000MHz
Memory Clock @ 800Mhz @ 5-5-5-15 2T
DDR2 Voltage @ 2.1V
Northbridge Voltage @ +0.1V
SouthBridge Volt Control @ Normal
CPU NB VID Control @ 1.225V
CPU Voltage @ 1.425V

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I've been at this since yesterday afternoon and I'm stumped on what's wrong with the computer. I'm testing the Mushkin set again, which I RMA'd before. Using Memtest86 v4.3.7 with 4 CPUs found, started, and 1 CPUs active. Currently been at it for 2+ hours and I got the following results:

2 passes, 2 errors. Both errors are on Test #8.
Error Confidence Value: 236
Lowest Error Address: 00030c60ddc - 780.3MB
Highest Error Address: 00030c60ddc - 780.3MB
Bits in Error Mask: 00001000
Bits in Error - Total: 1 Min: 1 Max: 1 Avg: 1
Max Contiguous Errors: 1

I guess I should add that my motherboard may be faulty? I noticed my SSD is running at SATA 1.5G speeds while the HDD is running at SATA 3G speeds. DVD burner and USB ports doesn't get recognized half the time either. I honestly wouldn't be surprised if taking it back and forth from London to Toronto at least 8 times in the past 4 years damaged something...

[David (PassMark)]

Bits in Error Mask: 00001000
Bits in Error - Total: 1 Min: 1 Max: 1 Avg: 1

This makes me think it is a RAM error.
Try testing 1 stick at a time and / or try underclocking the RAM & CPU a bit.

It could be the CPU or motherboard (I mean they sold that Phenom II X3 as a 3 core CPU for a reason, so turning on that 'bad' extra core then overclocking it is in some ways asking for problems)

I would be surprised if the other issues (SSD speed and DVD issues) are in anyway related to what appears to be a single bit error in your RAM. In technical terms, it sounds like a clusterf**k of problems.