Apricot,
The official version of the software is 3.18 but the Beta version started at 3.5. You should be very comfortable with using AC before going to beta. I don't think there was ever an official 3.2 to 3.4 version.
I must give Jon credit, the betas have been very stable, but that is not guaranteed. Remember you may be working with your patient database, and you must update it thus it might not work back with 3.18 without wizardry.
Having said that, I played with the beta version for about a week before putting it in one of my two offices. It has been fairly stable, although I have found a few bugs. Some bugs are there from 3.18. It does have some nice enhancements though.
I have been working with AC since 2002 ( version 1.28 or so, I think) this is more stable than some of the version 1 software, but it depends on your comfort with the program.
