TOCA3 pc locking up?

Hmmm, just installed TOCA Race Driver 3 about a week ago and now my
pc locks up whenever I play the sim? I'd appreciate any ideas on how
to cure the problem....

Appears to happen at random, I can play TRD3 for five minutes and it
happens, or I can play TRD3 for two hours then it happens. The pc
just locks up, the screen goes black, but I can still hear the game
sounds, but nothing happens, the controls (wheel, joystick,
keyboard, mouse) do not respond, and I have to do a hard reset to
get the pc working again.

NB: This is NOT heat related as I run pc probe and there are no
sudden increases in heat when the lockups occur.

I presume this may be due to the starforce drivers and/or McAfee
anti-virus, as I previously had a similar problem with TOCA Race
Driver 2, but the problem was cured by disabling McAfee before
playing TRD2. However, turning off McAfee does NOT seem to cure the
problem with TRD3?

For info the pc is as follows:

Asus Asus A7N8X Deluxe m/b based PC (in Antec case) with 400w psu
and AMD Barton 2500 cpu using 1Gb Crucial DDR ram, with a 128Mb
Radeon 9600 Pro graphics card. Two 120Gb SATA hard drives, FDD,
Pioneer CD-RW and Creative Labs DVD player (& 5.1 speakers). Hitachi
19" CRT monitor unit. Using Win XP (SP2). Using latest drivers for
all hardware.

Thanx