Several month ago I also had the same problem like you.
Using any 3rd party software to read NTFS hardisk on my Mac always corrupt certain file & even wipe out all data.

I try to use Parallel so that I can transfer file into NTFS hardisk, but no luck. It always say 'Destination folder access denied'.

I want to keep my external hardisk in NTFS format since majority of people using Windows, and I want Windows user can write & read the disk.
My friend also always come to my house to copy files, movies, etc into their NTFS hardisk.
I can't use the 3rd party software on my Mac also since it always corrupt the file & the hardisk.

What I did was using an old Windows CPU and connected it with my Mac using LAN cable.
Then use the network to transfer files to NTFS hardisk. (My workstation is Mac & PC side by side)
If you don't own a PC, you can buy a cheaper 2nd hand Windows netbook. Not very economical if you just use it to transfer file and don't use Windows software.
But it just my suggestion. I use Windows software sometimes & the solution works with me.

This post has been edited by generalkam: Dec 18 2010, 08:32 AM