Actually, on D6, you can. I had a patch in D7, but it got removed by DBTNG.
Nancy Injustice anywhere is a threat to justice everywhere. -- Dr. Martin L. King, Jr.
From: "Metzler, David"Setting
'#default_value' => array('SERVER01','SERVER02')
Is the correct form.
You cannot as you have done pass the results of a DB_QUERY directly to the '#default_value'.