I took a brief look. It looks like a strange problem. If I add the wantsToDisplayOnEmptyQuery to false, it seems to work, but I do not understand the real problem. At least not yet. Could you live with it for now?

GTSpotterMorph new
extent: (World width / 3.25 @ (World height / 2.25)) asIntegerPoint;
spotterModel: ((GTSpotter new)
processorsFilter: (CodePanelProcessorFilter new 
configuredWith: [ :aProcessor | aProcessor
actLogic: [ :aMethod :step | 
step exit.
aMethod ifNil: [ self new openInWindowLabeled: 'Code panel'  ]
ifNotNil: [
|panel|
panel := self new.
panel openInWindowLabeled: 'Code panel'.
panel newCardFor: aMethod.]];
candidatesLimit: 50;
wantsToDisplayOnEmptyQuery: false ]));
openCenteredInWorld

Cheers,

Doru