turn off shadow recording and only use manual. it will still cut the video into chunks of 4gb, but they should be 5-20 minutes long instead. if it is still only recording 1.53 seconds, then reinstall shadowplay, and get the most up to date version. another thing is to make sure that the file location is set up for videos, and that say your other software is encoding properly. try playing with the settings (i had the same problem with fraps, so i just stopped using it). also check to see if recording is funky with whatever game in particular you are trying to record