INSTALLED state never goes to NOT INSTALLED if the tool is not actually uninstalled. Are you sure its still present on the device?
Yes it does. The same thing happened to me.
I used to be able to locate my phone using the web site but when I tried it today,
it didn't work and it also says that it's not installed on my phone.
Luckily, my phone was just lying somewhere in my apartment, so I found it (had a friend call it)
and the program is still installed on it. I haven't tried anti-theft in a while but I noticed that the
web site looks different now, so they must have changed something when they redid the site.
It's a classical case of a "let's fix this thing that's already working fine".