This problem has been solved. Should anyone have a similar problem, I
thought I should share my experience with you. It turns out that I still had
an earlier version of Outlook active, even though I had installed Outlook
2007 (and thought it had removed all earlier versions of Outlook). When I
removed the earlier version of Outlook, the problem went away. Good luck to
you all, and I hope I have been able to save you some grief.

"WisconsinSteve" wrote:

I have received several .ics files from various travel web sites (e.g.,
expedia.com) showing my travel itineraries, but when I attempt to import them
into my Microsoft Outlook 2007 calendar, I get a message that the file is
"not a valid Internet Calendar file." Any ideas what I may be doing wrong?
Thanks for any help you can provide.