V4HD and SD ProRes 422

Hi Dave, this might be a silly question?
I have just migrated my mbp to a new i7 laptop pro so plenty of power.
(GRAIDed media on Express Card FW800, V4HD on internal FW800 early 2011 i7 mbp w 8Mb memory)

I have a SD paL ProRes anamorphic sequence on my timeline, which does not seem to want to playout.

What should the settings be for the V4HD ( there does not seem to be a V4HD preset for SD Prores on my system. Plenty of HD settings but NO SD)

Selecting "all frames" in "external video" setting causes both the viewer and canvas windows to freeze. (audio is still output over the SDI although no vision or just gash is on SDI video output.)

If I convert the sequence to DVCPRO50 Pal everything is fine as usual, so I can get the edit out to a digibeta without any problem, but wonder what I need to do to get ProRes SD to work without the extra render?

PS any sign of being able to use the MOTU with Avid MC or Premier from my mac?
The original media this time was avid meridian codec which I converted to ProRes.

Thanks Steve