Had the same problem, but decided to disallow post editing for anyone who has less than 10 posts and hasn't been a member for more than a month, did this by creating a promotion from registered to registered_ which then has full member privileges.
Causes a few problems, but solves more than it causes.

I've also disallowed PM privileges until the promotion, as we were getting a lot of PM spam.
Have this running on 3.8 and vb4.