kate error on exiting program

Binary package hint: kdesdk

When launching Kate from terminal I get this error message on exiting Kate:

X Error: BadWindow (invalid Window parameter) 3
  Major opcode: 20 (X_GetProperty)
  Resource id: 0x5e00ad4
X Error: BadWindow (invalid Window parameter) 3
  Major opcode: 20 (X_GetProperty)
  Resource id: 0x5e00ad4
X Error: BadWindow (invalid Window parameter) 3
  Major opcode: 20 (X_GetProperty)
  Resource id: 0x5e00ad4
X Error: BadWindow (invalid Window parameter) 3
  Major opcode: 20 (X_GetProperty)
  Resource id: 0x5e0002c
X Error: BadWindow (invalid Window parameter) 3
  Major opcode: 20 (X_GetProperty)
  Resource id: 0x5e0002c

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: kate 4:4.5.1-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.35-23.40-generic 2.6.35.7
Uname: Linux 2.6.35-23-generic x86_64
NonfreeKernelModules: fglrx
Architecture: amd64
Date: Thu Nov 25 15:30:38 2010
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
ProcEnviron:
 PATH=(custom, user)
 LANG=it_IT.utf8
 SHELL=/bin/bash
SourcePackage: kdesdk