Given up on 64 Bit. Eternal crashing with blue screen.
Now running Vista 32 bit. 4 Tuners (2 PCI Quattro S and 2 USB Tiny Twin DVB-T) prioritised to use PCI for watching and recording first. (slightly Better Picture with the PCI card).
Recorded TV shared to other MCE's using file and share permissions and local group policy. Crystal clear picture just using 54M Wireless. (Although I beleive this might be because it caches the files locally when it saved in the monitored folder- Just my assumption)
SPDIF is working perfectly through an Audigy 4 into external receiver delivering great surround sound on DVD and encoded tv shows. Programmed microsoft remote to turn receiver up and down rather than PC volume. The later would not control the volume with SPDIF digital output.
Free EPG working perfect with OzTivo stream.
http://www.epgstream.net really have made an awsome easy to install TV guide for vista And best of all no crashes.
After a days research and this awsome site I am a happy Vista 32 Bit customer.
I Would not try 64 Bit again. After much research it seems some people have been successful with 64 Bit but with many it has been a hill to hard to climb .