After many years of frustration on a couple of different PCs, PST now seems to be working but I have only got as far as finding the scalpel.
The trick was to create this Registry entry in a Win98 bottle, with DirectX installed.
HKEY_CURRENT_USER > Software > Wine > Direct3D > VideoMemorySize with a value of 8
This was done by following the instructions here
http://wiki.winehq.org/UsefulRegistryKeys?highlight=%28registry%29
and the need for it is explained here