I too am having some problems with TriLogi 5.0 in XP and ME. Specifically, I get a run time error "Illegal Memory Access", with the following statement:
IF F>5000 SETIO FFPUMP_EN
ENDIF
I also had a strange problem with Syntax errors on another If-Then-Else statement during compiling which seemed to be random and is hard to explain. I just deleted it and rewrote it, and it worked fine then. I am now moving these to TriLogi 4.1 and will see if I get the same problems.