I've been here eight years and never heard anything about bumping a post too soon. This is just in the wanted/for sale section, or what??
Yes, it is only for the Wanted / For Sale Forum. At the top of that forum is a sticky thread started by Jerry Forsyth (an AzB owner) titled "Forum Rules." Rule 11 reads as follows: "11) Over-active bumping is not allowed. If most of the replies to your post are bumps that is overactive bumping. Anything more than a single bump in any 48-hour period is over-bumping."