I just checked the installer, and indeed found that while we already try to remove
some files and folders in application data, the newer Snapshots2 as well as Immunization.ini & Statistics.ini were not added there (they're now).
See
this bug entry I just created thanks to your report
Maybe with the help of scripting in the uninstaller, we could ask the user if he wants those uninstalled. Not sure if the kind of uninstalling user I referred to would really know what to choose there though...
The TeaTimer icon seems to be related to the hard shutdown and restart when updating libraries... we probably should use kind of a softer shutdown that would allow TeaTimer to notify the tray area that it's closing down (but then, we don't want TeaTimer to shut down to easily... LOL )