What is wrong with this picture?

Top is output from "df -h", bottom is gparted. I suspect I'm missing a lot of free space. No problems other than that (yet). Can somebody suggest the best (non-destructive) way to correct this?

sudo dumpe2fs -h /dev/sda3: (source http://pastebin.com/nAvrdT4E)

Filesystem volume name:   <none>
Last mounted on:          /
Filesystem UUID:          9f6eff64-60d7-4eec-81d5-1e8acd818b38
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags:         signed_directory_hash 
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              1602496
Block count:              6406144
Reserved block count:     320306
Free blocks:              4842284
Free inodes:              1361222
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      1022
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8176
Inode blocks per group:   511
RAID stride:              32692
Flex block group size:    16
Filesystem created:       Sun Nov  8 18:18:13 2009
Last mount time:          Tue Mar  1 01:04:27 2011
Last write time:          Mon Feb 28 04:27:34 2011
Mount count:              16
Maximum mount count:      28
Last checked:             Thu Feb 24 06:23:39 2011
Check interval:           15552000 (6 months)
Next check after:         Tue Aug 23 07:23:39 2011
Lifetime writes:          227 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:           256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
First orphan inode:       268015
Default directory hash:   half_md4
Directory Hash Seed:      cc101517-e617-482b-a883-a72919419c84
Journal backup:           inode blocks
Journal features:         journal_incompat_revoke
Journal size:             128M
Journal length:           32768
Journal sequence:         0x001d3000
Journal start:            7787

fdisk and parted output per requests: http://pastebin.com/EGVH7Ken