I've created and recreated this simple sliding billboard several times. I even tried it on a blank html page but I get the same result.
The 3 panels are stacked and don't slide at all. Here's the test link:
webtestingsite.net/republictrusswerks.com/
Any help would be appreciated. I have a tight deadline with this site.
Thanks,

Hello Dave,

That is most likely caused because of the Line break type you use in DW.

To change the line break type you need to go to Preferences-> Code Format and in the field named "Line break type" choose "CR LF (Windows)"
and reapply the extension on your page.

Regards,