When you’re using software such as Acrobat Professional to print to a PDF file, the ‘save as’ dialog box comes up behind the active applications, also known as a ‘pop-under’.
Windows 7 has Aero Themes which are the cause of this problem.
In some cases, an update of the software can resolve this problem. The software may already been made compatible with the Windows 7 Aero Themes. If there are no updates available, you can disable the Aero Themes by Right-clicking the desktop / Personalization. Choose an Windows 7 classic theme and re-open the application. If the ‘save as’ window comes up, you will know the Aero theme caused this problem. You then just have to wait untill the software supplier comes with an update or use one of the simple, not so stylish classic themes.