Hi Jiri, thanks for reporting this bug.
I have created a Krusader bugreport to fix it upstream. https://sourceforge.net/tracker/index.php?func=detail&aid=1419207&group_id=6488&atid=106488 "[ 1419207 ] strange white stripe in panel" Confirmed on Krusader-1.70.0beta2+cvs-29Jan2006 using Debian Sarge. kind regards, Frank Schoolmeesters Krusader Krew http://www.krusader.org