I have servers with McAfee 4.5 and Open File Manager 7.003 installed and running at the same time, and when I try to run a backup in Networker, the backup doesn't even start. If I just have McAfee running, then the backup runs fine. If I just have OFM running, then the backup runs fine. It's a known issue with McAfee 4.0.3 and higher running with OFM 6.2 and higher. Both applications have their lock on the filesystem, and when a backup is attempted, it creates a recursive I/O (that's how it was explained to me). You must bounce the server to release this lock.
The trick is to let the OFM service start before the McAfee services start. You can do this manually, or use a third party utility that will delay the services.
My steps have been to set the McAfee services to Manual, bounce the server, let the OFM service start automatically, and then start the McAfee services myself. This allows both applications to run and it allows a backup to complete successfully.
I just wanted to share all this information with everyone. In response to your post, do you have any open file protection software installed? What are you using for Anti-Virus protection?