While it's more or less a negligible issue, I noticed that the launcher's skin has not updated with v0.6.0, but the launcher's window dimensions have. I can still access the "Start Game" button, but it's now cut off on the right.
I actually updated GRO on another machine, and it updated the skin.
I don't know if this will help, but here are some of the specs of my machine that may be relevant to the issue:
CPU: AMD Phenom II X4 965 BE
OS: Windows 7 Professional 64-bit SP1
Video: AMD Radeon HD 5870
RAM: 8GB DDR3-1333