apologies, its a windows 7 box, 12gb ddr3, quad processor i7 chip, ati 4870 card.
I am running CS5.
I started with the image then added a solid then particle world effect then a 35mm camera, after i added the camera i cannot see the particle grid until i select the particle effect iteslf but once i try and move from this point the grid vanishes until i stop moving.