So I still haven't found a successful workaround to this problem however may I suggest dropping a shortcut into the temp folder it defaults to. This is how I combat the issue and I save approx. 100 PDF's a day from outlook using windows 7.
To make matters easier include multiple "0's" at the beginning of the shortcut and they will always be at the top.
The above security fix did not work for me.
If you cannot manually navigate to the temp folder click on any PDF in the file and in its properties menu the folder location is listed which can be copied and pasted.to find the directory.