The fstab man page says that the option to allow users to mount the partition is "user" not "users".
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Exerpt from man fstab
The fourth field, (fs_mntops), describes the mount options associated with the filesystem.
It is formatted as a comma separated list of options. It contains at least the type of mount plus any additional options appropriate to the filesystem type. For documentation on the available options for non- nfs file systems, see mount(8). For documentation on all nfs-specific options have a look at nfs(5). Common for all types of file system are the options ‘‘noauto'' (do not mount when "mount -a" is given, e.g., at boot time), ‘‘user'' (allow a user to mount), and ‘‘owner'' (allow device owner to mount), and ‘‘_netdev'' (device requires network to be available). The ‘‘owner'' and ‘‘_netdev'' options are Linux-specific. For more details, see mount(8).
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Notice that I had to check the man page. I've been bitten with the "user" or "users" mistake in the past.
Also, even if the partition is mounted correctly there could still be problems with permissions on files in the partition's file system. In other words the files in the partition may not allow a normal user to view them. This could be due to account ownership combined with group ownership combined with restrictive file permissions.
If the file system is mounted at /mnt/Qfireball then issue the ls -l command on the files in the partition. Example:
ls -l /mnt/Qfireball
