in fairness, all our stable branch modules still work, e.g. any module wrote for any of the 1.6.x series will work with 1.6.1 - 1.6.4, and have done for over a year.... - yes we change the api on the 1.7 versions - its a _development_ version.
To say it short: use the stable version.
[Edited on 20-8-2006 by Rob]