Hi,
problem is caused by bad connection with server, or slow internet. If you have 128 or 256 kb it's slow for online gaming, you should buy new pack from IPS.
Also, it could be caused by too many programs which are connected on internet in same time. So, if you want to play your game, shutdown all other programs, or, if you don't know how, use Zone Alarm software, you can manage witch application can use internet, and which not.
In other cases, it's game framerate, if you low framerate it could be laggy, so try to change your Video Preferences and put higher or lower resolution, you'll be able to see changes.
At last, it could be malware on your computer.
