Yes that thread sounds rings a bell, did you ever find a solution? I'm still having connection problems, both USB and RS 485.
I can connect if the BRX is in program mode when I try to connect. I can connect and disconnect with no problems as long as I don't close DM Designer.
Once I close the program, I have to restart my laptop, switch to program mode and connect. That works most of the time, but sometimes I end up uninstalling DM Designer and reinstalling it. It's a pain, but at least I can get some work done now.