Bukkit

What steps will reproduce the problem?
1. Set up two regions, RegionA and RegionB
2. /rg setparent RegionA RegionB
3. Set up the RentRegion sign for RegionA
4. /rg info RegionA and then do /rg info RegionB - RegionA has a new member/owner but inheritance doesn't pass it down to RegionB

What is the expected output? What do you see instead?
WorldGuard's code seems to only check the region's inheritance once, when running the initial /rg setparent command. Therefore, when renting a parent region that has a child, the parent region's new owner doesn't get inherited to the child region.

What version of the product are you using?
The latest

Do you have an error log of what happened?
No need for one

Please provide any additional information below.

Ideally, IMO the solution would be to have an additional sign next or below the rent region sign that allows you to specify additional regions that are part of the rental or purchase such that hitting one sign would let you rent multiple regions at once.
Alternatively if the source was open I'd be able to do it myself :D

I am thinking your issue is that they can not build there? If so, then set the main region, ex. Spawn and shops are in the spawn region, set spawn's priority to -10 (region setpriority spawn -10). Then it will auto make anything made able to be built on if added to that region inside the main region.

Also, never put "Latest Version" as the latest changes.