IDD CS6 not compatible with IDD CS8

[PacosMother]

I have a CS6 file (created and last saved by IDD CS6), but my InDesign has been updated to CS8, and when I try to open the CS6 file, I'm told it was last saved as CS9--which I don't have yet--and it can't be opened. How could the file have converted to a version of ID that I do not have? The properties information for the file specifies that it is CS6.

[PacosMother]

I think I beat you to the punch--I uploaded it as a reply to one of my messages.