Downloaded file won't open when password-secured

Since moving from Acrobat 8 to 9, my passworded pdf file will not open once it is downloaded from the server.  My file was created as an .xls file in openoffice, then converted to pdf.  Password security was then set in Acrobat 9 pro (mac).  I works fine when not passworded.  Is there something I can do to regain the security functionality?  Note: the problem only occurs AFTER uploading to the server; it works as it should on my computer before that.