Drag&Drop doesn't work for some programs in launcher

For example, I need to send image file through skype or IM messenger. I take this file by mouse and drag it to launchar for opening minimized window. But all applications icons become gray, only browsers not. And I can't to open this windows and drop file.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: unity 4.28.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-16.29-generic-pae 3.0.20
Uname: Linux 3.0.0-16-generic-pae i686
ApportVersion: 1.23-0ubuntu4
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,compiztoolbox,snap,colorfilter,text,workarounds,neg,copytex,annotate,clone,commands,gnomecompat,move,place,regex,resize,rotate,screenshot,imgpng,water,zoom,grid,imgsvg,unitymtgrabhandles,expo,winrules,kdecompat,session,vpswitch,mousepoll,shift,ezoom,resizeinfo,mag,switcher,thumbnail,wall,ring,fade,scale,unityshell,scaleaddon,opacify]
Date: Wed Mar 21 13:36:40 2012
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
SourcePackage: unity
UpgradeStatus: Upgraded to oneiric on 2011-10-13 (159 days ago)