Problem with restoring a backup when DDL- or DML-scripts as text

We defined a custom-field "Database-scripts" to hold our DDL- or DML-script created to update the databases for our customers.

For e.g. "insert ...;", "Alter table ...;", "Update ..."

Every build from our product we collect the scripts so our application can automatically execute them.

When we now backup our database from your administration-menu and a few moments later try to restore it. It doesn't work.