Hi My configuration is
APEX 4.2 on Windows XP with APEX Listnere on Glassfish 3.1.2 Open Source Server Edition.
The database is 11G XE
Let me explain the scenario which is not working.
A Modal region which is having a file browse item based on WWV_FLOW_FILES and a button called add file.
When I click on add file it display a blank page and in the URL I could see http://localhost:8080/apex/wwv_flow.accept. But actually it inserted file in the table.
I have put wwv_flow* in Listener Configuration for allowed procedures.
I have another page where I have a page item which is based on BLOB column specified in item source attribute. And that is inserting file and displaying the pages correctly.