Chester,
This looks like it is related to a known bug with our erase necessary pages algorithm during Program Load. This bug will be fix for the CCS6.0 GA release.
In the mean time, you can work around this issue by modifying the default erase option to Erase Entire Flash (the "Use the Erase Options Specified Below" option in the On-Chip Flash view).
Please let me know if this works.
Thanks,
Ricky