Resource Rate Columns won't kepp edited title

Hi All,

Would you advice me to avoid following situation?

The column title at Resouce Unit Rate does not keep in next launch P6.

(I confirmed this in EPPM R8.3 and PPM R8.3)

Once I edited the column title to 'Special Rate' from 'Price/Unit4',

then the title changed properly.

But then I close the P6 and restart P6, the column title goes back to the original title 'Price/Unit4'.

Any suggestion will be appreciated.