vhs to digital conversion flickers only when captured
So once captured the file plays without these issues it's only during recording ?

Or are you saying that while the video is playing from the recorder but the computer is not recording it's okay &amp; then when you try to record it has those issues ?  

It could be an incorrect field setting in the software or buffering during recording. 

Have a look at the software recorders settings &amp; see if there's something for fields "upper" or "lower" or possible even deinterlace. 

Are you recording to an external drive or straight to your hard drive ? If you have the option try recording to a different drive.

And like Michael said if you upload a sample we can better see the issue