Hi Sadie,
I get exactly the same results as Michael mentions above. No problems opening it in Preview at all.
Your profile claims you are using OS X 10.4.5, is that still correct? Both Michael and I are on 10.4.8 so it could be that there was a bug in Preview that Apple have squashed since 10.4.5.
It's also possible it could also be something in your account that is causing Preview to error. One quick test you can do to help narrow down things is to try the same web site/ps file in another user account. This will help us to know whether your problem is local to your account or system wide. If you don't have another account you can use System Preferences -> Accounts -> [+] to create a test one (and [-] to remove it if needed).
If it fails there too, I'd recommend upgrading to 10.4.8 if possible.
