Any upgrade will show the Web tab, regardless if the node is enabled or not.

Probably the symptom I reported is that same bug. I'll post if I see it again.

My upgrade went similarly w/ the Web node. I normally don't have the Web node in the tree, but the first run after upgrading always shows the web node, even if you don't start it from the installer. I usually close that tab or select another node and immediately exit. I'm not sure which user account is running the program, or if it has elevated privs, after running the installer.

It's noted: http://www.ventismedia.com/mantis/view.php?id=10828

Upgrading to build 1662 no longer creates a duplicate tab but now it only shows the web tab plus the first tab that was open prior to the upgrade. The second tab that I left open prior to the upgrade did not open after the upgrade.

This is a known issue on upgrade: http://www.ventismedia.com/mantis/view.php?id=10828 Could it be that?

I've noticed that sometimes, if I shut down MMW with more than one tab open, when it reopens, tabs other than the first tab will be duplicated.
But, I can't replicate this at will. I've seen this for quite some time with 4.1 builds, I don't remember if I also saw it with 4.0.