Heh heh - thanks guys.
No it's certainly not always true that paying more gets you better goods, you only need a glance on ebay to see that where you see the same cheap generic things relabelled with enormous differences in price sometimes for the same kit.
Like I say, I"m very fortunately to have a good inventory of decent quality tools but the woodwork interest is relatively recent so I'm only learning, and therefore not rushing to wast money on tools that could be costly but not right for me.
I'm happy enough for now, and grateful for what I have.
Anyway, the new blades came today, and after some tweaking with the setup I am getting what initially appears to be nice straight cuts, so I'm naturally very pleased.
Have ordered more wood too for further variety of stuff to experiment with.
I can't yet fit my modifiied rollers guides until the smaller bore bearings come but they should help too once they're here.
Big improvement already though so thanks for all the advice guys - maybe it was just the blade, who knows?