Bukkit

Sometime running or jumping through glass causes person to be moved directly to the nearest non-breakable wall.

Example: I run and jump through glass. The glass breaks but instead of being on the ledge or inside I am still outside trying to stupidly run into a wall.

It should teleport you to the other side. Are you getting stuck in a block?

Sometimes if the window is raised up, you'll have to jump to actually get through.

I might not completely understand what's happening, im not sure. m