I was driving on the highway today and after 2-3 wot runs at "highway" speeds the engine cut out. I gave it a little gas and the engine was non-responsive. After pulling over, I tried restarting the engine but it sounded like it was trying to start but couldnt.

Has anyone had this problem or knows what it could be?

Someone told me that if the gas tank is less than 1/4 full, the fuel pump is overworked and can cut out. He suggest that I add gas. I added a couple gallons and the engine fired up normally. In hindsight I should have tried to start it before I added gas.

Has this ever happend to anyone or is this even possible? Could there be another problem?

By what you are explaining it could be a number of things to have caused this reaction. Not knowing your set up stock or single I could only give you're a few causes for this problem next time please be more detailed on your problem to help us further assist you.

1. Your O2 sensor has failed and gave out a wrong signal causing you to run to rich or lean giving you an unbalanced air/fuel mixture causing you to choke or stall out the engine. Check your O2 sensors if you have high mileage they might be going bad.
2. Your ignition system is starting to fail i.e. spark plugs, coil packs etc... resulting in a misfire. Make sure you check your ignition system and have the right plugs for the boost you are running.
3. Your fuel system i.e. injectors, pump, filter and lines might not be running correctly. Check your injectors and make sure they are clean and balanced and make sure your pump is running correctly as well as having a clean fuel filter to prevent any damage to your engine by running to lean.

There are so many things that could be the issue and I just stated a few not knowing your set up and what not, check all of these I listed above and reset your ECU. If you give me more details on your set up i.e. turbo, electronics, exhaust, fuel etc... I could better assist you if I haven't already.