I have jBPM Designer 3.0.8 installed with Eclipse 3.2 RC2 and WTP 1.5 RC2.
When I try to open a process definition it is opened using the plain wtp xml editor and not with the jBPM Designer. When I right click on the file, the designer is not listed in the 'open with' menu.
Is there something I can do to open the process definitions with the designer?
Yes you can do at least on thing.... search the forum. it has been answered multiple times. You could also learn eclipse file asociations.
Tip: configure eclipse that processdefinition.xml and gpd.xml are opened with the jbpm gpd editor.