MSI P6N SLI + 8 Gigs of Ram Vista Problem

Hey all,

The other day I decided I was going to upgrade to from 4 x 1 Gigs of G-Skill F2-6400CL5D- 2gbnq memory (with CL of 5-5-5-12/1.8v-2.0v) to 4 x 2 gigs of G-Skill f2-6400Cl4d 4gbpi-b memory (with cl of 4-4-4-12/ 1.8v-1.9v). The Motherboard I have is a MSI P6N-SLI-FI. The OS which is (Windows Vista Home Premium 64 bit) recognizes all 8 gigs no problem. However, I am having three problems with this. Regardless of all 8 Gigs being noticed the following problems are occuring:

First - Cas Latency is not set on 4-4-4-12, its set at the prior 4 gigs installed setting of 5-5-5-15. I had originally changed this manually thro bios but began to notice with Vista there was a loss in Physical Memory Available. I also saw a loss in performance, I am not sure that I set it up right initially. Which leads to problem two...

Second - While Vista 64 Home Prem. sees all installed physical memory (RAM) as 8.0 Gigs, it only lists Total Physical Memory as 3.0 Gigs..... as if it was a 32 bit OS, to go on with it, it fluctuates Available Physical Memory between 1.8-2.5 Gigs..... Total Virtual is listed as 6.21 Gigs Available is only 4.95 gigs.

Third - I cannot update my BIOS without a 32 bit OS because MSI auto update doesn't support a 64 bit OS unless I am doing something wrong or cannot find the file with MSI... I cannot upgrade the BIOS unless i revert or use XP Home maybe installed on my external HD. I am predicting that this might be the main cause of the following issues above.

The main question I have is how to increase Total Physical Memory so it registers higher than listed with Vista to increase system performance, also have correct CAS latency settings on the memory and clock it correctly with out loosing system performance, and if possible is there any way to update bios without having to make a boot disc so i dont mess up bios completely on this Mobo... Does memory remapping have to be used? and I am assuming this mobo doesn't have that feature since i cannot locate it.

System Specs as follows

MSI P6N-SLI-FI
Intel Core 2 Duo E6750
8 Gigs G-Skill 6400CL4D-4GBPI-B Ram
Nvidia XFX 8800 GTS
Segate 250 Gig HD
WD External 500 Gig HD
Gigabyte II Liquid Cooling System
Windows Vista Home Prem. 64 Bit


I'd appreciate any input,

Thanks!

That motherboard is only capable of recognizing 7 GB of RAM according to the manual, even though it will physically hold 8 GB.