Bukkit

What steps will reproduce the problem?
1.set a non-vanilla block as a core
2. generate world
3.

What is the expected output? What do you see instead?
crashlogs, incorrect blocks being spawned

What version of the product are you using?
version v2.3.2-dev.
tekkit 1.2.7 / Forge 9.11.1.965
Do you have an error log of what happened?

Please provide any additional information below.

A line like this to add a Thermal Expansion block to the list will crash the server. The generator doesnt override the generation rules.
If using Netherores they will come up as AIR unless the rules are not met (presence of netherrack to spawn against) also no non-vanilla ores will spawn outside of their maxheight setting.
    - 925:1-0.2
    - 732:7-1.0 produces activator rails.

I have tried all ores from all packs used with Tekkit 1.6.4. On occasion it will try to spawn a block but will not be anything thats in the configuration file, eg fills a planet with half grown wheat, or diodes that then cause a server crash. I have not included the crashlog as there is nothing in it relating to the generation, the only time it crashes is when its trying to call update_redstone_logic etc, sometimes its rails.

using the name or number works fine with vanilla blocks but neither work with non-vanilla.

The end result, any non vanilla ore either wont spawn (you get an asteroid with air in it) or it will spawn the wrong items (normally rails, diodes or another tile entity) and crash the server.