Hi the problem come from the ksoap you use.
It's the full for J2SE
Or blackberry is on J2ME. SourceForge.net: Files
and take the ksoap2-j2me-core-2.1.2.jar and don't forget to preverify it
preverify -classpath "C:\Program Files\Research In Motion\BlackBerry JDE 4.3.0\lib\net_rim_api.jar" Path_where_the_jar_is_located\ksoap2-j2me-core-2.1.2.jar
And recover the jar in the output folder located in C:\Program Files\Research In Motion\BlackBerry JDE 4.3.0\bin.
With this all should be ok