I'm having a similar problem. When I hit the painting the first time, a brief dialogue popped up, but no doorway opened. Every time I now hit the button all that happens is a comment about bunnies and the sky being so blue!
I am having trouble in the Halls of Chaos, where I am meant to push crates and barrels into the river. Try as I might I can't move a crate.
I'm on a macbook pro with the latest version of avernum 2 and every time I try and push a crate it just opens.