I was wondering if someone is already developing a mod that adds new blocks using spout. Ideally it should work by specifying a texture position (of course all the ppl on the server will need a texture, either because they downloaded or forced to them by another spout plugin) tied to an existing block id + an unused id. This way we could have marble blocks based on bricks or cobblestone or other blocks with similar properties, different materials for half-steps, colored glowstone and so on.
You should probably report these issues in the thread and be a little more descriptive. WHAT crashes, server or client? Are you using the dev build of spout and spoutcraft?