Hi, I've managed to use a secure wms in FlexViewer 2.4.<layer label="KMS Høje målebordsblade" type="WMS" visible="true"
url="http://kortforsyningen.kms.dk/?servicename=topo20_hoeje_maalebordsblade&client=ArcGIS&request=GetCapabilities&bbox=435464,6234974,480777,6295447&login=XXXX&password=YYYY&"
skipgetcapabilities="true" version="1.1.1"
visiblelayers="dtk_hoeje_maalebordsblade"
wkid="25832"/>
the URL includes the login and password, and if you can take the url and put it into a browser and get access to the xml-info of the WMS, then the rest should be straight on.Find the name of the layer you want to use, and put the name into visiblelayers="" and if you have more than one layer, seperate them by using visiblelayers="name1,name2,name3" remember no spaces.Hope it helps.Mads