Naw, i mean there is an option that is called 'all faces' as part fo the weight painting tools, in 2.60 it was under 'weight tools' on the tool sidebar and in 2.62 it's gone. The issue is that i want to paint on all faces under the cursor regardless of whether they'e visible , but it's stuck only painting on visible ones. so if i have a mesh with, say, a mouth interior sculpted, or nostrils that run up into the nose, i have no easy way of assigning weights to those verts. I DID, after poking round a bit, find that you can select the verts you want to assign a weight to and do it in the object properties, but that's a hell of a lot less intuitive than painting... it looks likethat's what i may be stuck doing though.