I suppose that you have used a 3rd party plugin, because this was not a functionality of ID CS3.
No plugins. It was part of Indesign CS3. It would automatically save the preview as a spread if you were working in a spread.
The feature was taken away when the 'pages' option was added to the File Handling preferences in CS4 or 5.
Note: It's an inDesign issue, not Bridge as Bridge CC displays the old CS3 previews just fine, as spreads.
Does anyone else work in teams on a publication that can give us some workflow ideas?
This has come up from time to time in the past. This is just the way it is
and I don't recall anyone coming up with a way to force the old behavior.
Yes it's a shame it hasnt been fixed as it's been requested numerous times over the last 3 years.