I know it's [I]wrong[I] to revive an old thread, but the advice about killing the process saved me having to reinstall. I spent four hours Googling and had tried nearly everything before finally stumbling across this solution;
Originally Posted by stress_junkie
That's exactly like the example that I showed you. That means that you must have a process that is using vi to edit the /etc/mtab file. The process id is 17717. Try this.
That should free up the /etc/mtab file. In the future don't edit the /etc/mtab file.
This solved the problem with the lock on /etc/mtab ,and I can now mount my ntfs hdd's. As an aside, I have a persistent install of 8.04 running on a 4Gb USB flash drive. Can't believe how smooth it is!
Thanks again to a fantastic community!