Error 7628 happened in TRANSACTION mode whiling trying to insert a table that has "WITH CHECK OPTION" foreign key≈ - response (1) by M.Saeed Khurram

Hi,
You have answered your question in the last line, when you use WITH CHECK OPTION , refrences are checked at transaction level. If you are inserting a row in the parent table and then the refrenced row in Child table in same transaction, it will not be succedded. as the the row inserted into A is not committed yet. To make this work, You will have to add two transactions to make this happen, or change it to soft RI WITH NO CHECK OPTION.