Best guess is that the file was inserted without also selecting the store by reference option. Double clicking only opens the files if store by reference was also selected. If you re-insert the file with store by reference specified, it should then open when you double click the container field.
unfortunately thats not the point, it has been entered by insert file and the reference box is selected. :c(
Can you open any other PDF files on this system by double clicking them?
If you launch acrobat and use open from the file menu can you open it? (That checks to verify that the exported file isn't damaged in some way).
I'm guessing here, but it sounds like a system setting in your OS has gotten changed and that this is keeping the OS from launching acrobat and using it to open the file.
no problem, but I also posted that doublecklicking the pdf itself does open the file with acrobat. anyway, I reinstalled Acrobat X now and voilá that´s it. now its worrking like it should with doublecklicking.
anyway thanks for your thoughts.