Can't confirm at all.
Installed 4.0.1 - without problems.
Uninstalled it.
Installed 4.0.0 - without problems.
Uninstalled it.
Installed 3.1.3.1 - withour problems.
Upgraded to 4.0.0 - without problems.
Upgraded to 4.0.1 - without problems.
Uninstalled it.
Everything works fine. Maybe there is problem with Marketplace installing?