Using Passport across OS

I formatted my 500gig Passport for Windows XP two years ago. My primary PC is now a Mac. I want to use the Passport for my active project files. I have copied files from XP to the PP and can copy them off the PP on to my Mac and then work on them but when I try to copy/save them back to the PP I get the following msg - this is file is locked (I can still save it to the Mac) or when I go to drag and drop from the Mac to the PP I get the circle with line symbol. I have read through all of the doc and can not find anything that tells me how to set the PP up for my needs. 

I want it to work like a flash stick. I can copy and save files to flash stick across operating systems no problem - why don’t I get the same functionality with the PP?

The drive is formatted NTFS for windows so it is read only on the Mac. Try NTFS-3G http://mac-free.com/download/NTFS-3G.html and the drive should be fully functional on the Mac then.

Joe

A much more stable NTFS layer for Mac however is Paragon NTFS, especially if you’re a lion user. 

http://www.paragon-software.com/home/ntfs-mac/

Not free, although a 10 day trial is available, and it’s less prone to data corruption than Joe S’s suggestion since it’s kept updated, whereas NTFS-3G I believe hasn’t been refreshed since Dec 2010 which pre-dates Lion.  And it doesn’t require the second MacFuse layer.