Graphics card screen corruption problem

Hi All

I have a problem with my year old desktop pc and random screen corruption when I startup the pc. Sometimes it does it once a month, but in the last week its happened it every day.

This is a video of what happens but its not always the same, but its always at startup. Usually anytime upto and including the windows login screen, but never before or during the bios screen. Once it corrupts I then need to hard reset, soft reset does nothing. All drivers are up to date.
http://youtu.be/6XtsjIUlyA4

I`ve tried replacing the graphics card and I still had problems and i`ve reinstalled windows 7. I`m thinking the next thing is to replace the psu? Whats strange is that it never goes wrong once windows is up and running, its only at startup. It also cause the external monitor (TV) to blank out and it freezes the pc ie caps lock,etc dont function. i`ve also tried it in someone else`s house with different monitor and the same occurred.

My equipment is as follows:
CPU: Intel Core i7-2600K (Sandy Bridge-DT XE, D2)
3400 MHz (34.00x100.0) @ 3511 MHz (35.00x100.3)
Motherboard: ASUS P8P67 PRO
Chipset: Intel P67 (Cougar Point) [B3]
Memory: 16384 MBytes @ 668 MHz, 9.0-9-9-24
- 4096 MB PC10600 DDR3 SDRAM - Kingston 9905403-439.A00LF
- 4096 MB PC10600 DDR3 SDRAM - Kingston 9905403-400.A00LF
- 4096 MB PC10600 DDR3 SDRAM - Kingston 9905403-439.A00LF
- 4096 MB PC10600 DDR3 SDRAM - Kingston 9905403-400.A00LF
Graphics: Zotac GeForce GTX 465
nVIDIA GeForce GTX 465 (GF100/D12U), 1048256 KB GDDR5 SDRAM
Drive: C300-CTFDDAC128MAG, 125.0 GB, Serial ATA 6Gb/s
Drive: WDC WD1002FAEX-00Z3A0, 976.8 GB, Serial ATA 6Gb/s
Drive: WDC WD1002FAEX-00Z3A0, 976.8 GB, Serial ATA 6Gb/s
Drive: HL-DT-ST DVDRAM GH22NS70, DVD+R DL
Sound: Intel Cougar Point PCH - High Definition Audio Controller [B3]
Sound: nVIDIA GF100 - High Definition Audio Controller
Network: Intel 82579V (Lewisville) Gigabit Network Connection
Network: D-Link DWA-525 Wireless N 150 Desktop Adapter
OS: Microsoft Windows 7 Home Premium (x64) Build 7601
PSU: Coolermaster 750W

Any Ideas??

Thanks alot