avr_fred:
Based on the above, I would suspect that either you don't have a Uno bootloader installed or the fuses are set incorrectly on the target device.
hmm.... i don't know how this happened - but it does seem the HFuse is not right.
i had used Nick Gammon's "Atmega_Board_Detector" sketch to confirm the bootloader when i first swapped out the chips - and to confirm the signature was 0x0F and not 0x14 (last part) - but only now just noticed the; HFuse = 0xD6 when i believe it should be 0xDA ?
i can't confirm it was ever 0xDA though - but it has worked all this time - on the UNO board.
does the programming chip running the Board Detector sketch make a difference ?
because it is now the 328_ which is in the UNO board.
previously it was the 328P, and i had to 'cheat-edit' the avrdude.conf to upload sketch via ISCP to the 328_ (on the breadboard).
EDIT: i only ran detect (with the 328_ and Nick Gammon's detector sketch) - not Burn Bootloader or anything else of a Write-nature (the sketch is still what was put there via the UNO board - just physically transposed from UNO to breadboard - no ICSP uploading has been run yet)
so... should i use avrdude to manually set/edit the HFuse on the 328P now ?
(could you reconfirm how to do this, i've read the ladyada tutorial on using it, but haven't actually put it in practice yet.)