The problem is well described and shown here: http://community.jaspersoft.com/questions/803290/first-line-indent-problem but really simple to be reproduce:
1. create a report with one text-field;
2. let the text-field be stretched with overflow;
3. define an first-line-identation for this text-field;
4. define justify as alignment for the text-field;
5. set a long value without line feeds that will break-page.
generating the report it will be able to see that the first page will presente the text-field with the identation and everything looks fine, but within the end of this page we can see that the last line in the first page is no longer justify and the first line of the second page will present the content with identation.
Sample attached to this issue.