Time line playback trouble

Hey all. After a month of editing on FCP3, my playback on the canvass is choppy. My TV monitor will only show the first frame that the play head is on while audio will play. If i hit the spacebar to stop play, the monitor will now display the new image the play head stops on. Normally, i would think that my memory or RAM or some such thing is being bogged down, but one minute it played fine, then without adding anything new to the timeline or browser, it now plays choppy. Am i missing an obvious thing here?

ugh.......trashed prefs......problem solved. i'm pretty sure the image size was causing the isssue.

dan

Sounds like you accidentally zoomed into your canvas or viewer.

Try this and see if it replicates the problem - press z to select the zoom tool, then click on your canvas to select it. Now try and play the footage. Is this the same thing you were seeing?

If so, in future, just select 'fit to window' in the small percentage box at the top of your canvas and viewer windows.