bug with pgAdmin 1.16.1 create database?

I'm using pgAdmin 1.16.1 on Windows and am seeing this curious behavior:

I'm connected to postgresql 9.2.4.

When creating a database, I click on the owner combo-box, and see what appears to be a composite list of available roles, then users.

I choose one of the users, who happens to have a name that matches the leading part of other names.

Having clicked on the name, the first matching (leading chars only) appears in the input field.

Eg:

Role name:

Abcdefg

User name:

Abc

Click on Abc, and I am shown Abcdefg in the dialog box.

Staying within the 'owner' field, now, using the down-arrow to scroll through the list, I never see Abc, and do not see all of the values that are shown when the combobox list is shown.

What's up here?? There seems to be something going on here that's not obvious.

Regards,
Peter