Good to know you got it solved
'cos I am pretty sure it should work...at least when I wrote the tutorial it worked. (It was Plus! 4 when I wrote the tutorial, and I didn't check if Plus! 5 broke things...so I was a little bit worried when I saw your post earlier today).
Anyway, to keep things a little bit more "geeky": while VARIANT_FALSE is usually defined 0, VARIANT_TRUE is usually defined as -1 (and it's a short -1, which is 0xffff), not 1. "true" in C++ usually translates into a positive 1 with common compiler implementation (of course, anything could work), FYI.