Hello All,
Hoping someone can help me with this.
I shot my Short on a Canon XH (HDV, widescreen, 23.97fps) and did all my editing in Premiere CS4 in HD. Everything looks great on the timeline and runs smoothly when I preview in Premiere.
I want to now export to H.264, so in the Options, that is what I choose.
In the section just below that I choose one of the High Quality, 23.97fps, 720p drop downs.
The complete film (~5 minutes) exports fine in about 20 minutes, but when i playback the footage, it's choppy and the sound is off.
Can anyone help?
Thank you.

Usually this is caused by background processes running. Check with either CCleaner to prevent processes from starting at boot time or use Process Explorer to kill processes. I recently had similar issues on a notebook, that showed choppy behavior while playing a HD H.264 TS file and ending/killing several processes solved the issue.

Thanks Harm.
So you think this choppiness is just during playback? The actual file is fine?

The same file when played on a Sony Vaio VGN-FW31ZJ was choppy and on the desktop flawless. Even when playing from a slow USB drive. It was only a matter of processes running in the background.

okay, i will double check.
thanks.

It was apparently the Quicktime player i was using.
When played with Windows Media Player, it worked perfectly.
Cheers.