The Package updater isn't threadsafe. When you lose focus to application and restore - the application screen doesn't redraw until the current package is installed.
Created attachment 136502 [details] The package updater doesn't redraw
It's not threaded at all as trying to do RPM operations from threads isn't entirely safe. I've made some changes in the devel tree to keep things as responsive as possible while avoiding the possibility of corrupting your rpm database :)