The new graphics card (Sapphire 5450 HD) really required a new build of Windows as the HDMI hand shaking appeared to've screwed up after install.
So, after re-install, the Sky Player & MSN Video entry point tiles were missing. Also, the download log was reporting errors.
Turns out this is down to some dodgy servers being presented via DNS - so I changed the primary Windows DNS to 63.251.62.33 & 192.168.1.1 (my netgear router) in the second. Flush DNS.Then, as admin, run mcupdate.exe -uf (does the uf stand for un fuck?!)
The entry point tiles reappeared. Mad.