I just tried it on a 64-bit Windows 8 machine (a Dell laptop) and it worked perfectly for me, so I think you'll probably have to go looking for another reason. Here are some things to think about:
Do you get any warnings or error messages?
Is there something unusual about your document? Is it very large or complex?
Are you able to create a PDF of the same document on another machine or with another version of Scribus?