Figured it out!

I figured out why the Release version wasn't working as expected. It seems that I have to turn off Optimizations for it to work. Geez... so now my Release version will be a bit bigger in size... -_- I'm lucky to have figured it out, I guess... I'll have to look into the lodePNG library code to see what's "incompatible" with Optimization. Oh well, at least I know why.