Flickering external monitor Mini DV to VGA adapter

Hi everyone,

Can anybody help me? I have MacBook Pro 13 and using Mac OS X 10.6.8. I wanted to connect it to the external VGA monitor to have extended desktop on it. I used for that purpose Networx Mini DisplayPort to VGA Adapter. On the external monitors I experienced flickering around letter edges, and some blurred letters sometimes. I tried to solve the problem with Mini DP VGA Update but there comes a notice: "The Updater could not find a Mini DisplayPort to VGA Adapter to update." I tried this on 2 different monitors Benq and Hyundai, which both work perfectly with my desktop computers, but all of them seem to show the same symptoms. Does anybody know how I can solve this problem and use the external monitors without flickering?