I am running 10.6.2 in Late 2008 Alu UMB. I have a Transcend 500 gig external, with NTFS partition of 250 gig. This NTFS partition has .dmg files. Among then, only a few dmg files show up with the usual dmg icon, everything else show up as blank icons, with .dmg extension, as if it were an unknown or unrecognised file. In file info the preview shown is the usual dmg icon and the file size is also right. When i double click, the dmg doesnt mount, infact nothing happens, and when i try to copy it to my internal hard drive, It says "One or more items in xxx.dmg can't be changed because they are in use". So am not able to use those dmg files. Please help me in fixing this wierd issue. Note: I have enabled native read/write for NTFS by editing the /etc/fstab.