Edges in GraphViz are drawn incorrectly

Binary package hint: graphviz

I tried to visualize a simple graph with graphviz/dot. It looks good, but: One of the Edges is drawn incorrect. It begins within the node instead of at the nodes border like all other edges (see attachment).
This problem already existed in Dot 2.8 (Debian 4). Since then, the formerly wrong edges are now drawn correctly and new ones are drawn incorrectly.
Looks like the problem has only "shifted" (see also http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=522535)

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: graphviz 2.26.3-4
ProcVersionSignature: Ubuntu 2.6.35-25.44-generic 2.6.35.10
Uname: Linux 2.6.35-25-generic i686
Architecture: i386
Date: Fri Feb 18 16:18:32 2011
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: graphviz