My shutter won't go when my hotshoe is connected?

I have a Nikon D3000 and I just bought a bower hotshoe flash that says is compatible with my camera. When I attach the hotshoe and turn it on the camera won't take a picture when I press the shutter button. I know the flash itself works because when I press the test button it flashes, and the shutter will go while the hotshoe is connected and turned off, but as soon as I turn it on, it won't take a picture. It focuses and beeps as though it is taking a pic, but the shutter never goes. Is there a setting I need to set the camera to or something?

Put the mode dial in the "M" position, set the shutter speed to 1/30, aperture f/5.6, with ISO set to 200 or so, see if it fires then. If it doesn't, there's something wrong with the flash. Honestly, I don't know why it's easier to get an off brand flash because it's cheaper, than to get one that has "Nikon" printed on the front of it. FYI, the SB400 is mad cheap, and it works… Everytime.