Hi, I install account_financial_report_webkit, account_financial_report_webkit_xls, report_xls so I can export report General Ledger into file excel. But when I try to print report into PDF, there is error like this

coercing to Unicode: need string or buffer, bool found (<type 'exceptions.typeerror'="">, TypeError('coercing to Unicode: need string or buffer, bool found',), <traceback object="" at="" 0x04757be8="">)

How can I print report into PDF file? Thanks