On the website of Nokia it says that firmware version 091.004 is available for the Nokia E72. This new version isn't shown in Nokia Suite, nor in the software update of the phone itselve.
How can I get the latest firmware for my phone?
Availability of update depends on Product Code / Region ..Also, for Network locked devices, update is possible only after an approval from the Operator.. Seems, one of the reasons is preventing you from getting the update. Your only chance of getting the update is trying thru' Nokia Care