Problem with insert - 1.12.0 RC1

Table should have some constraints (not null for instance) .

Open table to edit rows.
Put a value into any field and try to move from a row (now I assume that field with constraint have some wrong value, null in this case).

In previous versions PgAdmin shows error message and returns to edit mode. In 1.12 it stays in some weird state and all values are lost.

I reported this bug on pgadmin-support@postgresql.org (on 1.12 beta4) but there was no response.

Can anyone just confirm if it is a bug or I am doing something wrong.