Thanks to both,
Yes I have dabbled, but not with any live data yet.
I sort of hoped I might be able to capture a dump of a raw stream on the 400s and then have a look at it, but I think the sheer amount of data might make this impossible as the 400s has only limited storage space and even streaming it out somehow to a PC at 100Mb/s over the LAN, I think it would soon back up.
Don't have a DVB-S PCI or USB card at the moment sadly.
G