Video Studio X2 - project playback lagging

[vshart]

Video and overlay track are lagging during project playback
Does not lag when clip playback.
I need to preview all the tracks to make corrections.
Also note that when fully rendered it does not lag.
Even when playing single track lag is noticable.
audio, vocal, and title tracks are fine when playing back.
Its just Video and overlay track that are lagging

[BrianCee]

Oh dear - I'm afraid we need much more information to be able to help you - what sort of video clips - where did they come from - how did they get on your computer - what is the full specification of your computer (fill in the details in your profile)

Please read this topic :-

http://forum.corel.com/EN/viewtopic.php?f=63&t=29738

and fill in the information requested there