Thanks for all the answers. FWIW, the coded passwords didn't get changed in the udpate to v7 as (for example) mine wasn't _until_ I modified it at which point it became md5 encoded.
Some examples of the older encoding are (they seem to be a fixed length and shorter than md5):
.$dx1IaFEGidM
.$xnkZKKan5m2
.$dmQgpQk5Xsk
Thanks!--David