Changing source problem with monitor

I'm having a problem with my Samsung 2232bw and I'd be really glad if you can help me. I use it for both my pc and Xbox 360. The problem is, if I detach the data cable from monitor, when I reattach it it doesn't turn on. The blue light just starts to blink like it doesn't receive any data. Trying Source button or turning the monitor on/off doesn't help. I don't get any vision unless I restart my pc. Although I'm not absolutely sure if it's a monitor problem because this doesn't happen with Xbox 360. I have a Palit Sonic 8800gt and I use Windows XP sp2. Do you have any idea how to solve this? I appreciate any help.