I've experienced exactly the same problem (netbook to 40" TV at 19201080 resolution). The same netbook powering my 22" 19201080 LCS screen works fine. I have improved matters by using the best VGA cable I could find but I still get judder. My BB line is 20 Mb/sec and using Homeplugs at my TV location I can stream iPlayer HD without a problem so 4oD should be very easy for the netbook. I've come to the conclusion the netbook is simply underpowered for the job.
Amazon Fire HD 8 review: A brilliant combination of function and value – with one massive caveat