It would appear that a) this date field is not a field of type date or that space would generate an error. and b) you have a conditional value list with the "include only related values" option selected in manage | value lists.
If so, the fact that no new record exists until you enter data into one field and exit the field is indeed why you have an issue. You may be able to solve this by specifying the layout's table occurrence as the "starting from" table instead of the portals. Another option might be to remove the "allow creation of records..." option in the relationship an add a button to the layout for creating a new portal record. With this second option, you click the button and then, when you click or tab into the date field in the new record's row in the portal, you should have all in place for your current value list to work.
Than you. The Include only related values option is specified. So I will try one of your options.
Is it possible to sort the Value List in reverse order, it's simply a list of dates from a related table but it goes oldest to newest down the page, I'd like to reverse the order so the newest are at the top.
All "use values from a field" value lists sort in ascending order based on the value of one of the two fields specified in your value list. To present values in a different order is sometimes possible if you do not need both first and second fields to store visible data. Otherwise, you'd need to use something other than a value list to present the user with a list of choices. A portal listing the values where clicking portal rows selects a value and enters it into your field is a commonly used option for that as you can sort your portal in many ways not possible with a value list.