Comment 4 for bug 134378

Ah, I see where I went wrong.

Environment variables set in ~/.profile need to be exported in order to be present in x-session-manager and all its descendants. (Whereas they will be present in login shells even when they are not exported.) The line 'PATH=~/bin:"${PATH}"' (no export) and the fact that everything worked as expected when logging in on the virtual console made me think that those variables did not need to be exported.

After adding the appropriate "export" commands everything works fine.

Sorry for bothering you and thanks for your efforts!