I've been following along daily but had no time to actually look at it myself.
This can't seriously be how you intend to debug the whole application. It's just not viable.
This needs to be built with source level debugging one way or another.
Never in my professional life have I had these kinds of problems finding and fixing a bug with such obvious, repeatable symptoms. Those are the types of bugs I like to see assigned because they are so easily fixed. I faceplam at my carelessness, fix it, then move on.
My suggestion is still to get it building with VBCC so that you can use a source level debugger such as the one in SAS/C.
It couldn't take longer than debugging like this and the final result will be more reliable.