crontab -e # is illegal during initialization

Whenever I edit my crontab I get this error

Quote:

# is illegal during initialization reading /var/spool/cron/crontab.iYbP2T

Even after this error cron works as expected.

Also happens when I edit files using /usr/bin/vi, but not when i use /usr/bin/vim.

I'm sure I've been here before, or similar, when an aborted edit left a file behind. Deleted the file and everything returned to normal.

Can anyone push me in the right direction?