Prevent caching of pdf files

Currently on a secure Internet application we use the "Cache-Control: No
Cache" header to prevent information from caching on client machines.  We
would like to begin to provide pdf files via our application; however,
there is a known issue with accessing pdf files with IE 6.0 sp1 when the
no-cache header is used.  (Please refer to 
http://support.microsoft.com/default.aspx?scid=kb;en-us;812935
for details.)  As we have no control over the client machines accessing
our application, is there another way to prevent pdf files from being
automatically stored on the clients without using the no-cache header?

Thanks in advance,
-Brett