>>http://www.liberiangeek.net/2012/07/turn-on-off-offline-files-in-windows-7/
>>BTW, the "Offline Files" feature is ON by default in Windows 7
>
>I went to check this on my computer and it was not on. I do not remember disabling it previously. Perhaps some install program disabled it?

Of course, taking into consideration of how "Rube Goldberg"-ish Windows tends to be, it's hard to tell what might've caused the change... I figure there might've been some seemingly unrelated setting that got changed that impicitly turned off the feature in your case.