Random Freezes - Gigabyte GA-880GM-UD2H

G'day guys how are we?

My current Specs:
Gigabyte GA-880GM-UD2H
AMD Athlon II X2 Dual Core 255 CPU AM3 3.1GHz
Mushkin 4G(2x2G) DDR3 1333MHZ
HighPoint-RocketRAID 1740 - RAID 5

4 x Western Digital 2TB Green
4 x Western Digital 3TB Green
1 x Western Digital 500G Green - OS

I am having random gliches whilst watching *.AVI/*.MKV files whilst watching them in VLC Media Player,

It is also doing it during YouTube Videos (Mozilla Firefox)- I am running Windows 7 x64 Bit.

Now the RocketRAID port 1740 is still doing the initialising Stage of the RAID, It has taken about 17 hours so far and has done about 20% is this normal?

I also get weird gliches whilst watching movies, makes a weird buzzing noise for a second goes away and it's good for another 2 - 4 minutes, Is this because of the RAID card putting a lot of stress on the computer?

I did have the computer running smoothly with the same setup only with 3 x 2tb HDD's.

Would the PSU be playing up, All HDD's seem to sping up okay and have no other major issues.

Thank you in advanced.

Thanks,
Chad.