[TigerC10]

They use the the <PRE> tags to preserve the spaces, which means that it's being stored in the post with the spaces in there. That means that on submit, the code tag is being parsed and using some regex thing they're auto-formatting it.

When you have code that doesn't have appropriate space formatting, it's called "obfuscated" code. You should look into some de-obfuscating algorithms. If you can find something like that, it shouldn't be too hard to work into a hook.