After installation, no setting page shows up and php code does not display anything. Besides been present in the pluins list and allowing installation, it looks like the plugin does nothing.
FYI the following is a list of installed plugs in my WP251 setup:
* Akismet (v. 2.1.6 ) by Matt Mullenweg.
* Bad Behavior (v. 2.0.17 ) by Michael Hampton.
* Excerpt Editor (v. 1.1 ) by Andrew Ozz.
* Flash Video Player (v. 2.1 ) by Joshua Eldridge.
* Google XML Sitemaps (v. 18.104.22.168 ) by Arne Brachhold.
* HeadSpace2 (v. 3.4.2 ) by John Godley.
* Image Shadow (v. 1.0.0b2 ) by Rob Marsh, SJ.
* is_human() (v. 1.4.2 ) by Nick Berlette.
* Latin 2 HTML (v. 0.1 ) by Bruno Alves.
* Plugins list (v. 0.2 ) by Davide Benini.
* SEO Friendly Images (v. 2.3 ) by Vladimir Prelovac.
* Shadowbox JS dojo (v. 0.4 ) by Matt Martz .
* the_excerpt Reloaded (v. R1.4 ) by Kaf Oseo, Rob Bresalier.
* TTFTitles (v. 0.4.2 ) by John Leavitt.