Hi Glen,
This is a bit tricky as it has to do with internals of the web objects framework, sessions and database locks. I do not have technical details, but I will simplify the explanation (sorry about that, if you are interested in more details, let me know and we can have a call and I can get more). In many cases you can probably work fine in multiple tabs, but under a heavy load using multiple tabs can lead to create to deadlocks and eventually to significant performance degradation. As I said this is heritage of the framework and we have a plan to improve that behavior. Unfortunately it's a longer endeavor.
Peter
