current transaction is aborted, commands ignored until end of transaction block

[logic_openerp]

When I try to print all invoices for a customer, the next message appears :

Traceback (most recent call last):
  File "service\web_services.pyo", line 600, in go
  File "report\report_sxw.pyo", line 607, in create
  File "C:\Program Files\OpenERP AllInOne\Server\addons\base\ir\ir_attachment.py", line 42, in search
  File "osv\orm.pyo", line 2620, in search
  File "sql_db.pyo", line 76, in wrapper
  File "sql_db.pyo", line 118, in execute
InternalError: current transaction is aborted, commands ignored until end of transaction block

Thanks,
Guillaume ROCHE