I've tried GF 2.1.1 EE build 31g on Solaris and Linux machines.
GF 2.1.1 EE uninstaller doesn't remove correspondent entries from
productregistry file ( /usr/tmp/productregistry on Linux and
in /var/sadm/install/productregistry on Solaris)
With GF 2.1.1 entries in productregistry file, the attempt to install GF 2.1.1
EE or Sailfin at the same location, will create an installer message. This
message will tell that at this location was detected a previous installation
and your installation may have issues if you will do the installation in that
location. It happened, for example, if such directory doesn't exist at all.
I believe the uninstaller have to remove correpondent entries from
productregistry. Or at least this issue has to be documented