here a well known mounting problem:

Tuxera NTFS could not mount /dev/disk0s4
at /Volumes/BOOTCAMP because the following problem occurred:

CBCIO activated with:
cp.fildes=3
cp.blockSize=524288
cp.items=32
cp.mode=1
cp.flushInterval=1000
cp.alignmentSize=512
Did not receive a signal within 15.000000 seconds. Exiting...

whats wrong?
i have a imac 27" 2011 with lion 10.7 and want to install for gaming windows 7 ultimate 64
any suggestions?

Did you ever get a response to your post or find a solution? I'm having the exact same issue.

Please follow the below steps: -

-> Uninstall NTFS driver
-> Re-start again
-> Erase the file from the route: /System/Library/filesystems/ufsd.fs (before deleting the file, you should have anackup of these files)
-> Again re-install the driver of NTFS

Hope your issue is now resolve.

Have a nice day!!

Thanks,
Jimmy Ray Jit
Sr. Tech Support

I didn't see that file at that path. I saw something called udf.fs ... is that the file you meant?