Problems with Window 7 64 bit and FSX

Good Morning all
I have just bought a pc hoping that it would handle FSX as previous pc didn't do such a great job please see spec below

Windows 7 Home Premium
Intel(R) i7 CPU 870@2.93GHz
RAM 8.00Gb
System type: 64bit operating System
Graphics Card: GeFORCE GTX 460(ZOTAC)
Microsoft sidewinder 2

I have 2 problems and hope you guys might be able to offer some advice

1. A slight freeze only for about a instant every 3-4 minutes which i can so live with as last pc was like this but worse.

2. This one is a bit more serious as when a long flight is set say 6hrs or so and i toogle to the spot plane view and leave it running when I come back and try to move the outside plabe view around the aircraft the program freezes and i get a fatal error message and am asked if i want windows to find a solution and restart the program or just to restart the program.

expanding the error window gives me these details

Problem signature:
Problem Event Name: BEX
Application Name: fsx.exe
Application Version: 10.0.61472.0
Application Timestamp: 475e17d3
Fault Module Name: unknown
Fault Module Version: 0.0.0.0
Fault Module Timestamp: 00000000
Exception Offset: 8c000000
Exception Code: c0000005
Exception Data: 00000008
OS Version: 6.1.7600.2.0.0.768.3
Locale ID: 2057

Additional information about the problem:
LCID: 2057

I set a flight just before i go to work so when i come back i'm drawing close to the final stages of the flight with this pc this hasnt happened as on my return the pc has completely shut its self down (is this a setting for windows or fsx)

the above problem isnt plane specific and seems to work fine on the missions as far as I know

Hope you guys can help, thanks in advance

Darryl