[quote="linkman2004":3twy90a2]So, I'm working on my game, and I have it set up to where it will load the tile-sets for maps externally. The problem arises when the images are loaded during run-time using the sprite's "Load animation from file" action. Whenever they are loaded like this, the collision mask remain unchanged, even when they are set to per-pixel. This poses problems when the loaded tile is a ramp, but the collision mask remains a square.

Is this by design, or is this a bug that needs to be fixed? Thanks.[/quote:3twy90a2]
I do believe you can change the collision mode during runtime as well... have you tried that, or did you try to change the item properties in the design view?