It sounds to me like you have a corrupted bootloadable image on the kitprog device. The good news is that it is not hard to re-load. It is exhaustively documented in the CY8CKIT-042 PSoC Pioneer Kit Guide (http://www.cypress.com/file/46056/download) in section 18.104.22.168 (Restore PSoC 5LP Factory Program Using Bootloader Host Tool). It should just take a few minutes to get the kit refreshed.
Let us know if this gets you back up and running!