We have recently upgraded to RTC 3 and I have been seeing a change in behaviour when I submit a changeset for review that I don't understand.

When I submit the changeset, I now get a dialog saying:

You have unchecked-in changes that might be overwritten or may result in errors when you suspend. Do you want to check-in the changes before doing the suspend?

The only options from this dialog are "Suspend", "Cancel" or "Check-in and Suspend".

Why am I being asked about suspending changesets when I am submitting it for review? What changes are being suspended? What changes will be checked-in if I click the third option?

To date, I have resorted to clicking cancel and then manually adding a review to the associated workitem.

Any help as to what is happened here would be appreciated.