Hi,
Thank you for highlighting this behaviour.
Sheet names are now generated either by picking names from the SHEET_NAMES parameter, if it\'s set, or by constructing unique names based on the sheet\'s report name.
If there are multiple reports with the same name, sheet names based on report\'s name will be generated as reportName #i, where i is the index of the current report in the reports having the reportName name list.
More, if One Page Per Sheet is set to true, the Page k info is appended to the sheet name (k is the current page index).
If you prefer to give each sheet a personalised name, you should construct a String[] containing all sheet names (pay attention when One Page Per Sheet is set to true) and set it as SHEET_NAMES parameter.
All these features were commited on the svn repository (http://scm.jasperforge.org/svn/repos/jasperreports), and you could get them and try them.
Regards,
sanda zaharia