I've an external HDD of 500GB and in HFS+ format. It works normally on my Mac running OS X 10.5.8. After I plugged it into a machine running Windows, I found a vacant partition of 128MB and formatted it to NTFS. I used Paragon HFS+ for Windows to read and copy files.
Now I'm not able to write to that disk on my Mac. What is the problem?
diskutil list? – slhck♦ May 23 '12 at 17:48