Older graphic cards and drivers especially Intel based chips used on old laptops can fail to render the Qt front end correctly. This can range from anything to mashed text to full graphical glitch distortion. On some windows this will manifest as a very fast connection spinner animation ie Turbo Mode. On a certain few it will mean that the application crashes out.
On Windows 7 this can be partially resolved by switching from the aero theme to the windows basic theme. This will remove a lot of the shadowing and transparencies in the new app, but will force software rendering rather than OpenGL.