I can confirm this too. Even clicking on "Mail" from the notificaton icon, the same thing happens.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to thunderbird in Ubuntu. https://bugs.launchpad.net/bugs/878100 Title: Starting thunderbird from startup apps or CLI opens second icon in launcher Status in “thunderbird” package in Ubuntu: Confirmed Bug description: To reproduce: Add thunderbird to startup apps (or run it from the command line). Expected: The existing thunderbird icon in the launcher should become activated. Actual: A second thunderbird icon is added to the launcher. ProblemType: Bug DistroRelease: Ubuntu 11.10 Package: thunderbird 7.0.1+build1+nobinonly-0ubuntu1 ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4 Uname: Linux 3.0.0-12-generic i686 NonfreeKernelModules: nvidia AddonCompatCheckDisabled: False AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24. ApportVersion: 1.23-0ubuntu3 Architecture: i386 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: colinl 1687 F.... pulseaudio BuildID: 20110929181644 CRDA: Error: [Errno 2] No such file or directory Card0.Amixer.info: Card hw:0 'NVidia'/'HDA NVidia at 0xf9ef8000 irq 20' Mixer name : 'Realtek ALC888' Components : 'HDA:10ec0888,14627369,00100001' Controls : 36 Simple ctrls : 21 Channel: release Date: Wed Oct 19 12:11:12 2011 ForcedLayersAccel: False IfupdownConfig: auto lo iface lo inet loopback InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012) IpRoute: default via 192.168.1.1 dev eth0 proto static 169.254.0.0/16 dev eth0 scope link metric 1000 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.100 metric 1 IwConfig: lo no wireless extensions. eth0 no wireless extensions. Profiles: Profile0 (Default) - LastVersion=7.0.1/20110929181644 (Running) RfKill: RunningIncompatibleAddons: False SourcePackage: thunderbird UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 11/20/2007 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: V2.4 dmi.board.asset.tag: To Be Filled By O.E.M. dmi.board.name: MS-7369 dmi.board.vendor: MSI dmi.board.version: 1.0 dmi.chassis.asset.tag: To Be Filled By O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: To Be Filled By O.E.M. dmi.chassis.version: To Be Filled By O.E.M. dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrV2.4:bd11/20/2007:svnMSI:pnMS-7369:pvr1.0:rvnMSI:rnMS-7369:rvr1.0:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.: dmi.product.name: MS-7369 dmi.product.version: 1.0 dmi.sys.vendor: MSI To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/878100/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

