I hate my Apache, but at the same time I can't live without it. Let me correct that. I LOATHE my Apache. I hate its random lockups, the horribly unstable drivers, the terrible performance, the clunky WM6 interface, the "touch curve" at the bottom of the touchscreen (making it literally impossible to press a menu item located in the center of the bar), the software-controlled charging, the power problems, the notification hangups, the LACK of notification for calendar events...
But anyway, what this topic is about is the WM6 application installation database. Particularly, why mine is totally screwed up - and where it's stored!
Because of Windows Mobile's small size, it's possible to to a full filesystem search for a text phrase rather quickly. In my case I was looking for "evolane" as a part of "Evolane eTcl engine", as that was one of several applications that refuses to install properly - or even uninstall at all.
I ran Sprite Backup on my PPC just before reflashing. I then bought, and restored, portions of it back onto the newly flashed PPC. However, it seems that the restore also screwed up that application install database, so it now thinks that everything I had installed before is already installed (which it's not...), and if I try to actually install something I had before, it says something to the effect of "that's already installed, you need to uninstall it first, would you like to?", followed by "that failed to uninstall, would you like to continue?". It will proceed to install, then say "installation was unsuccessful" although it would still work fine.
But that's the problem. I can't get it to uninstall. When it is installed, I can try uninstalling it from "remove programs", and it'll say it's unsuccessful, and if I want to remove it from the list of installed programs. "YES". It simply moves up the list. I tap it again, repeat. Stays there. Over and over, I can do it as many times as I want. It doesn't install, it doesn't remove.
Now, since I spend many bored hours at work tinkering with my PPC, I had tried various things. I tried searching the registry for "Evolane" and removing all associated entries. No more "evolane" in the registry at all. Then I try searching for files named, or regarding, "evolane" or "etcl" in the filesystem. Nothing relevant. All the program's files are gone. There is no reference to "Evolane Tcl Engine" on my whole Pocket PC.

God damnit.
Where the heck is this database stored? I can't find any reference to it in the whole writeable filesystem. Is it stored as a ROM file? Why can't I find that stupid thing?! And is there even a tool that can fix this?
(edit: BeelineGPS also does the same thing, as does NetFront. I also finally managed to find a way to decouple the phone from the PPC so TomTom doesn't complain! Woot for dotFred.)