Very often operations on network drives slow down the whole opus. Is there any setting enabling the running of listers in separate threads or processes?
Listers are already separate threads (and file copies etc. are separate threads from those, too). (Running them in separate processes wouldn't make much difference when they're already in separate threads.)
If one window is slow because of network activity on another thread or process then something in that window must be querying the network as well. It's hard to give more specific advice without knowing what you're doing that is slow, but if you give some more detail then we might be able to suggest something.
Sometimes Opus hangs and double clicking on Desktop to open a new Lister doesn't work. After a while it unfreezes and then the new Lister appears. I don't remember a specific scenario at this moment so I will update this post when I encounter it again.
When that happens, do you see something similar if you try to access the same drive using Windows Explorer?