Mary Beth,
What version of ActivInspire do you have? Do you get this error when trying to import all Power Point files? What version of Power Point do you have? You may be getting this error message because the "Preview Pane" is enabled. Disabling the "Preview Pane" or closing all open folders appears to allow Inspire to import correctly. You may want to try and open ActivInspire and then import the power point. (case# 254852)
Thanks!