I suffered a brain-fade and appear to have some libs compiled with one version of Java and some with another, hence the error. Well, at least it resulted in some tests for DNATools. ...we now return to our regular programme... -- -= Keith James - kdj@sanger.ac.uk - http://www.sanger.ac.uk/Users/kdj =- Pathogen Sequencing Unit, Wellcome Trust Sanger Institute, Cambridge, UK