Switching binding context disable input

Hi,

I have a splitApp, on the left is a "master" list of customers and on the right is a "detail" form.

When I select a customer from the list, the detail form is updated with his informations.

I can also edit them and save them but only once. When I start editing the name and then switch to another I cannot type in the name field,

if I come back to the previous selected user I can edit the name field.

If you have any idea, please answer !