A copy of a crosstab from within the same iReport JRXML file will never populate with data properly.
Steps To Reproduce:
1) Setup Data
2) Create CrossTab
3) Copy and Paste CrossTab
4) Run Report.
1) Copied Cross Tab as similar structure to other Crosstab with data
2) Manually modifying crosstab is not possible, and does not fix this problem.
1) In the XML structure find your broken crosstab, and edit the XML UUID for the CrossTab->Report Element tag. Removing it works just as well.
2) Switch back to designer mode, a new UUID (if removed) will appear.
3) Run the report, report runs as expected.
When copying objects ensure that a new UUID is always created.