Did you install the latest icon.library v46.4.256 from Aminet ?
You could also try the new concept of my of my IconDemoADF.rar which uses LoadResident instead of SetPatch v44. Of course, you can replace the supplied OS 3.0 files in that package with those from OS 3.1.
http://eab.abime.net/showthread.php?t=64079
Unfortunately, I can not help you with WHDLoad, because I never play any games.
Just tried DeluxePacMan and WHDLoad 17.1 with AmiKit 1.6.2b and with the original icon.library 45.1: WHDLoad throws thousands of Enforcer hits there, so it seems to be buggy !! Is there a newer version already?