I can't single step through my IF ENDIF statements.
 Correct. They don't allow for this.
──────────────────────────────────────────────────────────────────────────────

 The first thing you should know is that the IF..ELSEIF..ELSE..ENDIF
 construct is NOT identical to the DO CASE..ENDCASE construct.

 The IF..ELSEIF..ELSE..ENDIF is similar to the DO CASE construct in that you
 both may execute one of several statements depending on the outcome of an
 expression.

 The main difference between the two is that when an IF..ELSEIF..ELSE..ENDIF
 construct is compiled, the line numbers are not stored within the object
 module so when you come to debug them, the debugger can only show the top
 line  of the construct and then the program jumps straight to the statement
 following the first .T.  evaluation.

 The DO CASE..ENDCASE construct has line numbers stored with each CASE line
 in the object module and therefore you are able to single step through a
 DO..CASE..ENDCASE construct without any 'sudden jumps'.

 You may get around this problem by replacing your IF..ELSEIF..ELSE..ENDIF
 constructs with DO CASE..CASE..OTHERWISE..ENDCASE statements.

 Or, you may compile your application by including the MrDebug.Ch file - in
 which IF..ELSEIF..ELSE..ENDIF constructs will be pre-processed into DO
 CASE..CASE..OTHERWISE..ENDCASE statements

 To summarize.... if you include MrDebug.Ch in a .prg then all
 IF..ELSEIF..ELSE..ENDIF constructs will be replaced with
 CASE..CASE..OTHERWISE..ENDCASE constructs.