I switched my JSAPI version to 3.14 and now, when I have point features selected, the symbol does not show up. It works fine if I only switch back to 3.12. It also works fine for the line features.
Interestingly enough, I could not find any of the samples in which point features are highlighted when popups are used on a point features identify style tool.
Here is the current symbol setup in case it it helps:
selColor = new esri.Color([0, 255, 255, 0.6]);
selLine = new esri.symbol.CartographicLineSymbol(esri.symbol.CartographicLineSymbol.STYLE_SOLID, selColor, 10, esri.symbol.CartographicLineSymbol.CAP_ROUND, esri.symbol.CartographicLineSymbol.JOIN_ROUND);
selMarker = new esri.symbol.SimpleMarkerSymbol(esri.symbol.SimpleMarkerSymbol.STYLE_SQUARE, 20, selLine, selColor);
mainMap.infoWindow.lineSymbol = selLine;
mainMap.infoWindow.markerSymbol = selMarker;