TRUE : Episode 5 - A Locke Flashback?

Update: As per the spoiler from Secretagentman, Episode 5 is NOT a Locke Episode. This is the benefit of having a Rumours section.

I was sent an email from someone from Hawaii who has been up to the filming areas of Lost and reports that they have seen scenes being prepared for a Locke Flashback episode which would be Episode 5. I'll try to confirm this with other sources.

Update: This LINK seems to confirm this story.

The Convention Center turns into Sydney Airport again on Monday 8/28 - a Locke backstory scene.