Here is a tip if you suffer from intermittent hangs

[tractorboy]

I had a 2GHz P4 with 512MByte of 266MHz RAM. Studio 10 worked just fine.
I upgraded to a 2.66GHz P4 and 1MByte 400MHz RAM. Disaster! Frequent crashes with any CPU/RAM intensive process (like video editing!)

I searched this site and many others for a solution - but found none.

In desparation I looked at the bios, and in particular at the bus frequency settings, which I have always had set to 'auto' (the manufacturer's default).
I deliberately 'underclocked' the CPU frequency to 1MHz x 20 and the RAM frequency to simulate running my old set-up (i.e a 2GHz P4 and 266MHz RAM).
The software worked great - just as it used to.
Next, I manually set the CPU frequency to 133MHz x 20 and the RAM speed to 400MHz.
Result: faster video and no hang-ups!
I haven't bothered to research WHY the auto setting gets it wrong - I'm just happy that everything works as it ought.