We are doing OpenGL development on Parallels Desktop 5 with Windows 7 installed. When our application makes glReadPixels OpenGL API call, it causes ocassinally OpenGL to swap back buffer to front buffer. This is against OpenGL specification and causes screen flashing and flickering in OpenGL applications. Formerly we were doing same developement on Parallels Desktop 4 which did not have any issues. glReadPixels behaved correctly in previous versions of Parallels Desktop. Please correct this issue as soon as possible! Has anybody else faced this issue or screen flickering issue in OpenGL applications while running Windows 7 on Parallels Desktop 5?