Steps to reproduce:
1) Create Java Application, main class is opened in the editor at the end of project creation
2) Type inside the main class main() method:
List <String> list = new ArrayList <String> ();
3) Move pointer to the end of "List" and press ctrl-space, choose "List <E> (java.util)"
4) The result is that java.util.List is imported that is correct (import is listed twice, but another issue was filed 
on that, maybe already fixed).
5) Move pointer to the end of "ArrayList", press ctrl-space, choose "ArrayList <String> (java.util).
6) The ArrayList is imported but the string becomes wrong:
List <String> list = new ArrayList<String><String> ();

This is quite annoying.
It occurs with the latest dev build (200807300201) and with 6.1 as well.