I've been at this for 2 hours almost, it worked at one point for some reason, but when i came back it didn't.

Here's what I've done:
1. plug in external (WD 320gb passport USB drive)
2. Mount the drive
3. right-clicked to Properties-->device-->clicked 'read only' box to uncheck-->applied and exit
4. right-clicked external [sdb1]--> change read/write mode-->'do you really want to change partition /dev/sdb1(fuseblk) to be writeable' yes-->ERROR: remount command failed. Maybe there is another process accesing the filesystem currently.

Someone help, it was working earlier but not now and now im pretty frustrated.