Migrate detail from dev to prod with Import and Export

Hi,

I created a new detail in dev by the section wozard -> New Detail (there, created a new detail based on existing object).

How can I migare the edit page and with the new detail to prod with import and export?

I always used to export the detail schema first and than the section edit page and it worked good. All the sudden in the last week I can no do that this way, when I try I get the title of the detail section on the edit page but whenI want to add a record to the detail or get to the detail setup, I get a message: "Detail not registered in the details lookup"

Please help asap!!!

Thanks,

Chani