Installing/Uninstalling new package deactivates another (3.1)

[mtkr0l]

I replicated this behavior when installing/uninstalling new packages.

1. I have Fisheye, Stickies, Treasury and Wiki installed. When I installed another package, the Fisheye package was deactivated. Same thing happens when I uninstall a package. The Fisheye package that was on top of the list is deactivated.
2. Related: So, I check Fisheye activation to activate it again and click "Modify activation" button. After page refresh, the package is checked, but the package does not appear in the main administration menu. I have to click "Modify activation" again to get Fisheye/Photos to be seen in the menu. I'm not sure if this is the desired behavior.