I found a nice new, rarely trigger Magento bug.
In one of our projects, we have an example file to create new products:
data-upgrade-example-new-product-import.php
Beside this we had data scripts:
data-install-1.0.1.php
data-upgrade-1.0.0-1.0.1.php
data-upgrade-1.0.5-1.0.6.php
Unfortunately data-upgrade-1.0.