Hi BLUSpy. The problem is with the product and not your settings. Attempting to prevent a thread from being seen completely is proving tricky as there isn't one central place I can do it but instead I have to find all the different searches and fix them all. I did look at this problem last weekend and found the place in code I needed to hook in to didn't actually have a hook I could use.
I appreciate it's not very good though so I will attempt to resolve the issue. Unfortunately due to work time schedules I can't say when I'll get to look at it, but the more people I know this is affecting the more embarrassed I'll be about it so it will get sorted at some point!