Some Blocks with Extended IDs are being Randomly Replaced

[markkrueg]

Here is an odd "block replacement" we have found. Player quote:

Some blocks are being replaced by other blocks in a strange mathematical pattern. I've only observed this with clay, wool, and slabs so it probably only happens to blocks with extended IDs (ie 35:1 vs 35).

Here is an identical picture on the original mcregion world:

[markkrueg]

I have isolated this specific .mcr file and done a conversion with this file and one other; and the results are repeatable. No errors are produced by AnvilConverter.jar during conversion.

So I will be able to test this issue quickly when we come up with a potential solution.

[markkrueg]

As requested, here is an example world to use for testing.

swapped_wood_world.zip

[Awzaw]

Fixed, sorry it took so long!