I just updated to EE 2.7.1 and now using Channel Form in place of Safecracker. I can't seem to sort these two bugs:
1) Any existing 'file' custom fields behave as if they are required, throwing up the error "You did not select a file to upload." if left empty. (edit: this also happens in the CP, not just Channel Form problem)
2) The datepicker creates undefined text like this: "2013-10-01un1efine1". It does work if I use {field:my_date} but then get the localised/fixed select menu, and the only way to remove it is to hide it using css.
I'd be interested to hear anyone else's problems with the Safecracker to Channel Form problems.