@Michelle McGuire,
Hmm, I'm not sure what would cause it to slow down that dramatically. What type of data are they entering? I'd have to defer to @Ed Hayman on that but I'd actually recommend submitting a support ticket if you haven't already. Perhaps there is a formula or a circular reference or something that is causing the slow down. Regardless, support should be able to help identify the cause and help with a resolution.
Cheers,
Deb
------------------------------
Debbie Hagen
Apptio
------------------------------