11.04 shuts down after around 15 minutes of online video or less, every single time-Collection of common programming errors

It will be very difficult to say what might be wrong. You have not mentioned any thing about the H/W you are using. Desktop PC or laptop, Graphics card etc.

One cause of the shutdown might be over heating. Playing videos using Flash is a quite processor intensive work. Normally playing video heats up the CPU more quickly. One thing you can do is check the CUP temperature while you are watching Hulu.

Install lmsensors : sudo apt-get install lm_sensors Check the temp: sensors

If you see your cpu temp is shooting up high while playing the Hulu, indicates you have some problem with your cooling system. Check it out, let us know so that we can debug the issue further.