Moving a zoomed image with image overlay on it - overlay is drawn many times

[Péter Trombitás]

So the title isn't perfect, but I think the attached screenshot says it all.
I guess that the image should be redrawn each time it moves.
I think I can solve this problem though I'm sort of lost in the code.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: geeqie 1:1.0-10
ProcVersionSignature: Ubuntu 3.2.0-36.57-generic 3.2.35
Uname: Linux 3.2.0-36-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
Date: Sun Jan 20 15:08:18 2013
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
MarkForUpload: True
ProcEnviron:
 PATH=(custom, no user)
 LANG=hu_HU.UTF-8
 SHELL=/bin/bash
SourcePackage: geeqie
UpgradeStatus: No upgrade log present (probably fresh install)