Saraqael you're welcome! We learn stuff from helping; the organization of your CAPX for one. Flawless! I'm stealing it :)
You should still use multiples of 16, it's good practice, and from what I've read it's good memory-wise.
The stitches didn't disappear because of the odd height number. My guess is, the engine is trying to wrap half a pixel from the top into the space that is half a pixel from the bottom. By taking away that pixel, it has nowhere to draw the wrap-around bit.