[scala-tools] Eclipse plugin from trunk, update strangeness

At updating the plugin (Eclipse 3.4.1, Help -> Software Updates -> ...) I get
the error:

"Cannot complete the request.  See the details.
Format error in file: /tmp/p2Encoding2688268050629787634.opb."

At a time of the message showing that file in /tmp doesn't exist. For building
the plugin I use a script shown below.

Any ideas?

//------------------------------------------------

# cat ~/bin/scaPluTrunk                        
#!/bin/bash                                              

SVN_ROOT=/wrk/dev/scala/SVN/

# update

cd $SVN_ROOT/scala
svn up            

cd $SVN_ROOT/scala-library
svn up

cd $SVN_ROOT/scala-plugin
svn up

cd $SVN_ROOT/scala-plugin-aspects
svn up

# build

cd $SVN_ROOT/scala
ant all.clean
ant fastdist

cd $SVN_ROOT/scala-library
ant clean
ant dist

cd $SVN_ROOT/scala-plugin-aspects
ant clean
ant dist

cd $SVN_ROOT/scala-plugin
ant clean
ant dist