I'm posting this topic because it was archived in 2009 without a solution.
When clicking a pdf link in Safari for windows (4.0.3) it opens a new window but does not show the pdf. The window remains blank with "canceled opening page" in the status bar.
For me this hangup was caused by the environment variables TEMP and TMP being set to an inaccessible location.
Basically, to open a pdf file Safari needs to safe it to a temporary location. Then Adobe reader can open it from that location. The location is set in the environment variables TEMP and TMP. For me they were set to "D:\Temp", however D was a CD drive hence the file could not be saved let alone opened.
Solution: Go to Control Panel>System>Advanced tab>Environment Variables then check/change the user variables TEMP and TMP to something you are sure is accessible like "C:\Temp".
If this solution works for you please write up a response. Good luck.