http://en.wikipedia.org/w/api.php?format=xml&action=query&list=allusers&aulimit=3&aufrom=A

produces the following result:

<api>
<query>
<allusers>
<u name="A" userid="rMW5006869606c6"/>
<u name="A & D Phone Cards" userid="4364737"/>
<u name="A & F" userid="13421528"/>
<u name="A & F" userid="13421528"/>
</allusers>
</query>
<query-continue>
<allusers aufrom="A & K Reid"/>
</query-continue>
</api>

The user A & F is listed twice when it should only be listed once.

Version: unspecified
Severity: normal
URL: http://en.wikipedia.org/w/api.php?format=xmlfm&action=query&list=allusers&aulimit=3&aufrom=A