I installed PDF Creator 0.9.8 on Vista Business SP2 (UAC enabled). After that, i tried to make PDF from notepad. PDF Spooler allways turned me back to Save AS dialog - Overwrite - Save As - Overwrite - Save As.... I discovered in Options - Directories that Temporary files are stored in C:\Program Files\PDFCreator\Temp\ were Vista don't permit deletnig even user is administrator. Then I click "Reset all Settings" and "Save". With PDF Print Monitor opened I check to see that changes were saved to <Temp>PDFCreator\. Then I was able to finish Save As function finaly and clear temporary files from the Spooler directory. I checked even in Registry in HKCU\Software\PDFCreator\Program that "PrinterTemppath" shows to the righ place (C:\Users\username\AppData\Local\Temp\PDFCreator\). 
After that, I closed PDF Print Monitor. Next time, when I tried to make another PDF document with PDF Creator, same thing happened and I discovered that location for the Temporary files are turned back to C:\Program Files\PDFCreator\Temp\. This happens allways when I start PDF Creator from the Programs or invoking from Print.
Then I tried to change in Registry HKLM\Software\PDFCreator\Program value for "PrinterTemppath" to show the desired folder (for example c:\temp), restart the computer and PDF Creator, but without result that I expected. The Temporary files again showing C:\Program Files\PDFCreator\Temp\.
Only thing that helped me to resolve this issue was disabling UAC. After disabling UAC, things start working as expected. Inserting the values in HKLM\Software\PDFCreator\Program for the "PrinterTemppath" I was able to force setting over the user settings. After enabling UAC, issue starts from the beginning.
Disabling UAC is really something that I won't to do in production, so I kindly ask if there is some other way wich can be applyed throug GP (or some other metod) in enterprise and solve this problem with UAC enabled.
I also found other workaround (giving the Change right for the \\Computername\Users group to the C:\Program Files\PDFCreator\Temp\ folder) but it is also somethihg that I don't recomend.
Thanks.