I was able to read and write NTFS filesystems normally in Mountain Lion, but after the upgrade this stopped to work.
I installed ntfs-3g and fuse4x using homebrew in Mountain Lion and followed the instructions displayed by homebrew to finish the installation of fuse4x kernel extension.
To try to solve this problem I removed ntfs-3g, fuse4x and fuse4x-kext and reinstalled them. But this didn't solve my problem.
Does anyone know how to solve this? Thanks.