chocky, the pagefile use looks good. I have noticed some things, though. The number of processes is jumping around -- 62, 55, 66. Some fluctuation is normal when nothing is going on. If that was you rebooting, launching apps, and closing them, then no worries. If not, let me know.
I also notice that the CPU usage is non-zero, 3%, 4%, 7%, which is OK if you know what is running. It could be the OS running background tasks, as whs suggests. Maybe a restore point, or the indexer, or superfetch. At some point, though, it should calm down. Lots of non-paged Kernel memory, relatively, which also suggests that the OS is working. What kind of CPU is it?
Your numbers are all within normal ranges and 3 snaps in time is not a good indicator. You should clean out your Startups as much as possible -- I see iTunesHelper in the process list and you don't need it. Do you run a security suite (firewall, AV, malware checks)? Obviously, you have Spybot S&D, but anything else? It never hurts to scan for malware, especially when things aren't working just right.
What are you using for video encoding? I use TMPGEnc 4.0 Xpress for best quality and speed.