Hi,
Please check your version of Java.
As written here, http://chemicalcovers.sourceforge.net/?page_id=10 , this could be related to a bug in Java under XP:
"
About Java and ChemicalCovers
ChemicalCovers needs Java 6 to run. But they are different version of Java 6.
We heavily recommend you to use Java 6 update 10 (or better)
".
2009-08-02 12:46:28 UTC in ChemicalCovers