Within Redmine's member searches (for instance on the 'Members' settings for projects), you have the ability to search for users, however if 2 or more users have the same name, there's no way to distinguish them. In the attached file, you can see there's no way of distinguishing two different John Smiths (short of inspecting page source code to look for user ID number and looking that up).

Can each of the entries here include the user's login after the names? For instance, displaying "John Smith (jsmith)" would remove any ambiguity.

Having the login names displayed in the list of actual group members (under the heading of 'User / Group') would be useful as well - otherwise in order to check who people are one has to click onto their profiles.

About your application's environment
Ruby version              1.8.7 (x86_64-linux)
RubyGems version          1.6.2
Rack version              1.1.1
Rails version             2.3.14
Active Record version     2.3.14
Active Resource version   2.3.14
Action Mailer version     2.3.14
Active Support version    2.3.14
Edge Rails revision       unknown
Application root          /opt/redmine/redmine-1.3.0
Environment               production
Database adapter          mysql
Database schema version   20110902000000

About your Redmine plugins
Redmine Github Hook plugin   0.1.1

I'm using Redmine 1.3.0 (issue looks to be present in source code trunk, however).