thunderbird lists 0 bytes size for attachments

Tested on xubuntu trusty daily image:

When dragging and dropping two files to a new email as attachments, the file size displayed is always "0 Bytes".

It should display the correct size instead.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: thunderbird 1:24.2.0+build1-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-12.32-generic 3.13.4
Uname: Linux 3.13.0-12-generic i686
NonfreeKernelModules: wl
AddonCompatCheckDisabled: False
ApportVersion: 2.13.2-0ubuntu5
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: daniel 1483 F.... pulseaudio
BuildID: 20131206222113
Channel: Unavailable
CurrentDesktop: XFCE
Date: Wed Mar 5 22:20:41 2014
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2014-02-26 (6 days ago)
InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Alpha i386 (20140225)
IpRoute:
 default via 192.168.0.1 dev wlan0 proto static
 192.168.0.0/24 dev wlan0 proto kernel scope link src 192.168.0.212 metric 9
Plugins: Shockwave Flash - /usr/lib/flashplugin-installer/libflashplayer.so
PrefSources: prefs.js
Profiles: Profile0 (Default) - LastVersion=24.2.0/20131206222113 (In use)
RunningIncompatibleAddons: False
SourcePackage: thunderbird
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/29/2009
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A06
dmi.board.name: CN0Y53
dmi.board.vendor: Dell Inc.
dmi.board.version: A06
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: A06
dmi.modalias: dmi:bvnDellInc.:bvrA06:bd07/29/2009:svnDellInc.:pnInspiron1011:pvrA06:rvnDellInc.:rnCN0Y53:rvrA06:cvnDellInc.:ct8:cvrA06:
dmi.product.name: Inspiron 1011
dmi.product.version: A06
dmi.sys.vendor: Dell Inc.