one or more invalid checksum segments

i have a DSP5 tune on my 06 LLY and when i read the calibration data from the ecm at the end a message comes up that says "this calibration containes one or more invalid checksums and is unsafe" ect... by looking at the calibration deffinition file number it goes on to the pcm as a DSP5 tune but comes off with the stock .calz number and there is no custom os there. i tried doing a full reflash and nothing changed. the truck still runs the way it should and all the configured DSP tunes are there. i just cant read off the pcm. anyone know whats going on?

You cannot read a DSP5 tune. Flashing only, that's why you save the DSP5 tune is a safe location.

i read a DSP5 tune from an LB7 before and never had this problem. but i do remember reading about this when i first ran the DSP tune.

On the 06 LLY you can't read back the tune, this is a limitation of the Bosch ECM. Was never an issue with the LB7 or early (non Bosch ECM) LLY.
With the invalid checksums, some hand held tuners will cause this error, so if it still has that tune in then that is your problem.

ok then there is no problem, thanks for your help.