Which version of richfaces are you using?
in rf3.3.x you can override the default ExtendDataTableRenderer (by editting the faces-config.xml)
Removing the following block:
writer.write(convertToString("\n " + convertToString(encodeDragDropChildScripts(context,component)) + ";\n //"));
should be enough!
(But I haven't tried this before)
This will disabled the drag and drop feature for every extendedDataTable in your project!
Thanks for the workaround, but it should exist a property called rearrangeMode=none, for example.
I think there is currently no such property