Thanks for response – I have found the way round this. Just in case anyone else has the same issue:
Export using Quicktime compression, then DV Stream, PAL 48k, select 16:9 and encode. Export file to PC and bring into ProCoder. Adjust the size of the output window (in target settings) to whatever you want – in my case 356×200. Works really well.
Panic over.
Martin.