Bug: Tiled 0.7.1 for OS X that locks stamp brush tile location

This may be QT specific or even OS X build specific. Unfortunately I have not found the steps necessary to reproduce this issue. It usually first occurs when I load a project, and select the stamp brush tool. Immediately a tile is drawn the upper left corner of my canvas. If I select the eraser, it immediately erases the tile without clicking anywhere on the canvas. Clicking back on the brush tool draws a tile again the same place. Clicking elsewhere on the canvas may not draw anything. But when it does, the last draw location is highlighted and stuck on the screen, and depending on what tools I choose (the stamp brush or eraser) it will either draw or erase on that same location. It's as if my mouse button is stuck down on the last location instead of releasing. Sometimes I can "break free" of this problem, but I'm not sure what the process is.

Start by trying to reproduce the behavior described when loading a project and selecting the stamp brush or eraser on OS X. Observe whether the canvas position remains stuck after tool changes or clicks, and narrow down whether it is specific to the Qt or OS X build. Done requires a reproducible case and a verified fix for the stuck tile interaction.

Written by the indexing model from the issue text.