there are 3 methods that invoke the UAC. (
http://www.itninja.com/question/suppressing-uac-using-act)
fusion, heuristics, installer detection.
as an example setting a manifest against an exe which is triggering because of installer detection methods will not stop the UAC prompt from showing up.
when is the UAC prompt happening during execution of the shortcut, or execution of a function of the running application?
you may need to crack open procmon to see if this is happening due to file permissions etc. - See more at:
http://www.itninja.com/question/suppressing-uac-using-act#sthash.TBeuwLiu.dpuf
