Well - the VBA option isn't ideal as I can't control the speed very well.

I've tried the split-and-animate-together option, and with that you have to
try and sync up the motion of the second part to tag itself onto the end of
the first part - you can't park it on the end to start with or it sits
outside the renderable area and thus behaves as if it were one large image

I've managed to get something reasonable results by splitting into 1024x768
chunks and sliding each one in and out in turn, and they just about work, but
you can get seams between them.

The WMV option is always an option but 1024 x 768 movies are not small
things, not really top quality in the sort of format that's going to play -
and not too reliable really.

I was hoping that I'd just missed something - but sadly it doesn't look like
I have....I'll have to rethink things a little.

Doug