Version:           4.7 (using KDE 4.7.2) 
OS:                Linux

when I try to start dolphin, it takes a long time to startup (about a minute).
Debugging the issue, I found errors of this form in the .xsession-errors file:

kioslave: ####### CRASH ###### protocol = thumbnail pid = 8851 signal = 11

I tried using the procedure found here:
    http://techbase.kde.org/Development/Tutorials/Debugging/Debugging_IOSlaves
to generate and capture a traceback, but when I do, kdeinit4 complains
about not be able to communicate with klauncher. 

I found some info for turning on debug messages.  I turned on debug info
for kio_thumbnail, and got these, possibly unrelated, messages before the crash:
kio_thumbnail(7619) new_creator: videoPreview: new_creator
kio_thumbnail(7619) VideoPreview::VideoPreview: videoPreview constructor
kio_thumbnail(7619) VideoPreview::create: videopreview svn
kio_thumbnail(7619) ServicesFactory::videoBackend: videopreview: backend:  1
kio_thumbnail(7619) ServicesFactory::videoBackend: videopreview: Selected mplayer backend
kio_thumbnail(7619) PreviewingFile::isBlacklisted: videopreview: file extension=" "" "
kio_thumbnail(7619) MPlayerVideoBackend::findPlayerBin: videopreview: customargs= ""  ;;;;  ("")
kio_thumbnail(7619) MPlayerVideoBackend::findPlayerBin: videopreview: mplayer not found, exiting. Run mplayerthumbsconfig to setup mplayer path manually.


I found some older issues, and as a work-around, I turned off all previews
Settings -> General -> Previews.  This prevents both the slow start and the
crash from occuring.



Reproducible: Always

Steps to Reproduce:
Start dolphin from app widget, media insertion, or command line.


Expected Results:  
Dolphin starts up in a few seconds.