Yeah, I got the cause. The most strange thing is - I already fixed this without thinking in v0.1.5 and couldn't reproduce it until I went back to the first public release >< Anyways, it's more of a graphical bug at this point and it won't affect your gameplay in the upcoming release. Since we are 3 days away from the next public version, I don't see a reason to make a hotfixed version for the first public update.
Thanks for the tip!