well, this is true. I know PDF Generator works on Windows XP and it is also unsupported. I have seen PDF Generator works on Windows 2008 Server and it is also unsupported. If there is somebody here having PDF Generator working on SBS 2008, please let me know.
If I knew it works, I would spend time to make it working for the customer. If I know it don't work, I will not waste the time.
You might be able to get it running on SBS 2008, but it won't be supported.
Just make sure your customer understands that.