Bug involving the Channel spell and Order IDs

I don't know if someone else has discovered but I thought I'd post it anyways as it's a rather strange bug.

Run the demo map below and cast the spell. It will do f*ck all.
Open up object editor and reset, or change, the Base Order ID value for the custom spell Silence. Now try again, wee?

It took two bloody hours to figure out what the hell was wrong with a simple dummy ability being cast.

I don't particularly feel like opening up the map, so could you describe what happens?

the dummy doesn't cast the spell if the orderid conflicts with that of the channel-based ability