Unnecessary download step

I've recently upgraded from Adobe Reader 7 to Adobe Acrobat 8.0 Standard.
 
Now, whenever I try to open a pdf in IE 6.0 I get a file download dialog box which requests me to save or cancel. Once I save the pdf it then opens a further dialog box which allows me to open it. Before when I was using Reader 7 I used to get just one dialog box which allowed me to open the pdf.
 
Is there anyway way of avoiding this unnecessary download step?
 
I use win xp sp2.
 
The message I'm getting on the file download dialog box is:-
 
Do you want to save this?
 
Name: test.pdf
Type: Adobe Acrobat Document, 49.1 KB
From: TestServer
 
"The file you are downloading cannot be opened by the default program. It is either corrupted or it has an incorrect file type. As a security precaution, it is recommended that you cancel the download"
 
thanks in advance