A refresh of the Mono 2.4.2.3 Framework Installer for Mac has been released. The only change in this release is a new version of GTK+ that resolves a number of known issues in MonoDevelop, including redraw bugs, control-click functionality, and Mac keybindings for standard GTK+ widgets. The GTK+ build uses a branch of GTK+ 2.17.9 maintained by Christian Hergert, sponsored by Unity.

You can find it on the downloads section.