Possible cause: Your partition wasn't cleanly unmounted in Windows, because you didn't use "Safely remove hardware" before unplugging your removable drive. Alternatively, you're trying to read a drive which has been left in a hibernated state (you put Windows in hibernation mode instead of doing a complete shut down).
Problem: My partition doesn't mount automatically!
Possible cause: Your partition is incorrectly marked as another file system in your partition table. This can happen if you use mkntfs on an existing partition without changing file system type in the partition table. To reformat other file systems as NTFS volumes in OS X, use the command line tool
diskutil with the verb eraseVolume. The format argument will be NTFS-3G. See man diskutil for usage info.Problem: Filenames with international characters are displayed incorrectly!
Possible cause: You haven't created the file ".ntfs-locale" in the root of the operating system, describing how to interpret international characters. This file is read by this package's mount utility script before mounting it to determine the correct parameters. If you type the command "locale -a" in the Terminal you will get a list of all locales available on your system. One of these should be typed into the .ntfs-locale file. (Note that the file will need to be called ".ntfs-locale" and NOT for example ".ntfs-locale.txt")
Problem: NTFS-3G is damn slow!
Possible cause: Is it really the connection to your drive that's slow? (For example a USB2 drive running in USB 1.1 mode...)
Anyway, NTFS-3G is currently noticeably slower compared to the kernel mode drivers that it competes with. I'm looking into adding some caching patches to speed things up.
I get around 10-15 MiB/s when copying files to and from my SATA drive. You shouldn't expect more than that at the moment.
Update: I can confirm that NTFS-3G is actually damn slow with USB2 drives. IDE/SATA drives work better, Firewire performance is unknown (if you have a FW drive, you could report your performance figures in the comments to this thread)...
Problem: NTFS-3G doesn't react properly to SIGTERM and thus slows down shutdown of the computer!
Possible cause: There is something that I don't understand with how NTFS-3G reacts in these situations. shadowofged, who provided the previous hazzle free package for NTFS-3G, solved the problem (or tried to... I'm not sure if it really worked on my computer) by installing a daemon listening to SIGTERM, and when activated automatically unmounted all MacFUSE file systems. This daemon isn't released as open source software, but I might rewrite it in the future as open source code, if the problem gets too annoying.
Question: How do I uninstall the previous NTFS-3G package (or whatever package...) that I have installed?
Solution: You probably don't even have to. The package is upgradable, so if you install the package over a previous version all of the old files that aren't being used by the new package are automatically removed. If you still need to remove some package from your system, you can fetch this universal package removal script, which lets you type the name of a package, and then reads the contents of the package receipt and removes all files associated with the package (including the receipt).
(Note that if you're trying to remove a previous package called "NTFS-3G", like an older version, the uninstall script packaged within the current NTFS-3G package will effectively remove the old package if you run it before you install the current one. So in that case there's no need for the universal script...)
[This post will be updated as new problems and solutions are collected.]