I can confirm similar behaviour with Intrepid Xubuntu and kernel 2.6.27-11.
Initially, have the 1 user created at install time (member of admin, adm, etc).
As this user launch the System>Users and Groups menu item. Select Unlock and authenticate. Add a new 'Desktop User'. On committing, the applet stalls for several seconds during which entries can be seen to be removed from /etc/group (eg, repeatedly run 'wc -l /etc/group' in a terminal). No user has been created. The group and passwd files have been ruined, as described in earlier reports.
If a user is created by other means no corresponding entry appears in the U&G list.
Victims of this bug should be aware of the update-passwd, pwconv and grpconv commands which will greatly help to repair the system.
I can confirm similar behaviour with Intrepid Xubuntu and kernel 2.6.27-11.
Initially, have the 1 user created at install time (member of admin, adm, etc).
As this user launch the System>Users and Groups menu item. Select Unlock and authenticate. Add a new 'Desktop User'. On committing, the applet stalls for several seconds during which entries can be seen to be removed from /etc/group (eg, repeatedly run 'wc -l /etc/group' in a terminal). No user has been created. The group and passwd files have been ruined, as described in earlier reports.
If a user is created by other means no corresponding entry appears in the U&G list.
Victims of this bug should be aware of the update-passwd, pwconv and grpconv commands which will greatly help to repair the system.