Ok that´s really crazy... I booted up the game again to try the first glitch (the game version I downloaded yesterday) and I didn't fall through the floor this time. It happened to me twice the other day so on the third try I siply avoided it, but now I can't get it to happen again. I will further test it. I'm on a Windows 7 64 bit btw.
Also thanks on the patches, and congratulations on the game!