I have the same problem with OE6 and ETrust Inoculate IT 6.0
If I am not logged onto the NT server, everything works just fine. If I am logged on and I have realtime disabled, all is fine. If I am monitoring incoming files the system gets unstable and balky. If I am monitoring both directions,(which company policy demands) all manner of nasty behaviour results. On one machine, the majority of the time OE gets as far as the splash screen, and sits there forever. Going to the task manager you find OE does not even exist - and there is no way to get the splash screen to go away short of rebooting the computer. Otherwise the system will "hang" with task manager showing OE not responding, and 100% cpu usage. If left for half an hour it MIGHT come back. Another possibility is it loads properly - possibly a little slow, then stops responding part way through downloading or opening a message.
Along with the other problems this product has had - and it's TOTAL inability to deal effectively with the BugBear situation, I am far from happy with InoculateIT and CA in general. As far as there support goes I often wonder if their agents have even seen the product - and some days even a computer.