Order of units in USES

I seem to remember that somebody indicated years ago that one needs to have certain IW-related units as the first ones in an interface USES section. Is this still the case?

I ask because I am trying to include MadExcept in some of my programs. All GUI (non-Intraweb) application run fine but all Intraweb application cause an access violation. 

Any suggestions to resolve this? Is it a known situation or something specific to my code?

Thanks