thanks for the replies anthony.

I think i tried too many things at once and got a bit lost.

it's now importing ok !

for the txt file which shows the warning message....

I had moved all my csv files except one - which i had tried to amend to uses commas inside the file rather than columns.

I then put the csv files back to normal (with columns). and took note of the NULL message.

I changed the IDNo field to accept NULLs and it then it started working.

However, as for the IDNo field - i don't want to import this and didn't think I was importing it (because under mappings i only have column 0 mapped to 1 field called postcode - so didnt think this field should matter, but maybe it needs to be NULL if data is not being imported into it - due to data being iserted into the adjacent column?)