You don't say where you are - if you're in the UK, I'm wondering why you used a roller at all, its not recommended at any time for lawns, either before you lay or sow seed or on a growing or mature lawn. Without knowing where you are, what type of grass seed you're using (if you're in the States, could be Buffalo grass for all I know), how heavy or not your soil is, how many times you actually rolled it and with how heavy a roller making it impossible to guess how compacted the soil might be, its hard to say whether simply raking up the top will be enough.

Yes we're in the uk. Had to use roller to level out the topsoil (8 tonnes of it!!). Think we'll persist as we are and see what happens, here's hoping! Thanks.