While you can hot swap the monitors, it just makes sense to shut down and re-connect. The time involved is minicle so it shouldn't be that long to do this. At times some configs. of the monitor may cause issue, so if things act up rather quickly then reset the monitor and/or setting via the OS and/or its video mgr. to do this. You may need to install the monitor disc to fully make use of all capabilities or install its s/w manager.
Yesterday morning when I turned on my home PC, it started acting very strangely. The display was very odd, with every window that I closed appearing as a ghost image, before it shut down. The mouse moved extremely slowly and anything I typed took a long time to show up. I had to leave for work, so didn't get back to it until last night. By the evening, all appeared well, and so I thought my problems were gone/over.