Steve your members renewal was processed but I have not heard from you as you said you where having urgent issues with permissions.
Your uploads and data directories must be 777 permissions to allow files to be uploaded and processed on your server. That is the generic explanation and known fact. Even vBulletin which you use state that there attachments and customavatars directories must be 777. Some web host server setups would allow you to upload and process files with directory permissions set to 755 but you would need to check with your host on there policies as that has nothing to do with our software specifically.
What I can tell you is that if your server is setup correctly and permissions are correct for the server environment to allow uploading then files should process correctly.