Create a page type with a required, non-culturespecific string property. Create an instance of this page, put in a space for this field and then translate the page. The translated page now has NULL for this field and since it is non-culturespecific you cannot change it (only on the language where it was originally created).

This is a problem because we do not do null-checking on required fields. Perhaps we should?

I am guessing behind the scenes EPiServer is doing a Trim on the field, discovers the field is an empty string and does not set the value for the translation.

I can see two possible solutions:

1. do not allow spaces/tabs/(whitespace?) for required properties (trim suer input before checking so check will fail)
2. do not trim a property when translating a page

Not entirely sure what is going on so my solutions could be wrong :)