launch cocoa-app (with gui) from launchd

I have been unsuccessful so far attempting to launch an xcode cocoa app
from launchd.  I have tried loading 2 different versions of a plist that reference either
the executable, or the .app bundle.  Neither works.  I noticed a prior listing explaining
that the actual exe must be referenced, not the .app bundle.  ps shows that the process actually gets
created both ways.  However, nothing appears.  I am able to launch the app successfully from a
script file and the cmd-line.  But when the script file (which launches the app) is run
via launchd, again nothing happens.  I am using WatchPaths, and the Program key has been set
to either the executable, or the .app bundle.  Any suggestions out there?
thanks...bob