Application looks frozen when working with big graphs

```
What steps will reproduce the problem?
1. Open application
2. Load a big graph
3.

What is the expected output? What do you see instead?
Application should look like before loading the graph.
Instead the application window turns grey, it gives the appearance that the
application is frozen but it is not. If the user waits long enough and the
computation ends the application window looks like it is supposed to look.

```

Original issue reported on code.google.com by `bombax` on 1 Mar 2012 at 2:54