Hey Thanks so much for getting back to me so quickly
System:
AMD Phenom 9550 64bit
4Gb RAM (another 4 on the way)
1Gb Nvidia 9550 GT GPU
Software:
Windows 7 64
After Effects CS5
Trapcode Particular 2.1.1
I have attached a screen grab of the comp and a grab of the render result, the particle layers are missing.
Please let me know any more details you need.
Thanks
Nick