I updated to latest 9.0.6.61665 from 8.xxx last week. I have this installed on XP 32 bit machine. I have one and only Oracle Client 11g Release 2 (11.2) for Microsoft Windows (32-Bit) installed. I have enabled multi session mode (by default). I am having trouble changing from one instance to another. I can't change from one session to another by using the log on item from the session menu. i.e., I am in DEVL instance and I want to switch to Prod instance I go to session and log on to production instance and it says I got logged into prod instance and PL/SQL Developer IDE displays to the PROD instance I just connected to. But, It is not, I am still in the DEVL instance. However, I can change the instance from one to another from the dropdown(LOV) from the display bar at the bottom panel of the IDE(new feature in 9.XXX). When I switch to different instance from the dropdown at the bottom panel the db connection at the top of the panel does not change. It is misleading and I only refer to what shows up on the top of the panel. Meaning, the session menu at the top panel is worth less. Is this a bug or did I got this installation wrong. I have only one Oracle client installed. I don't have any db installed on my machine. I connect to my client's databases remotely through VPN. Marco, Can help me out here.