Well now upon thinking about it further I think I know what has happened with F/A-18.. I run DXTweaker and that may have put in the alph blend injection to make it not do that in F-18..
I tried it in NASCAR2003 but was not able to reproduce it.. maybe because N2003 is DX8 and F-18 was dx7? IT did not seem to fully function under DX8 for some weird reason..