Error when testing the Acid Maps Code on a browser

[ngugi]

Hallo,
I am using geoservr 2.1.0 and am getting an error when I run the text script on the Acid Map code. The error is the following
This XML file does not appear to have any style information associated with it. The document tree is shown below.

<ows:ExceptionReport version="1.0.0" xsi:schemaLocation="http://www.opengis.net/ows http://localhost:8081/geoserver/schemas/ows/1.0.0/owsExceptionReport.xsd"><ows:Exception exceptionCode="NoApplicableCode">ows:ExceptionTextjava.lang.NoClassDefFoundError: Could not initialize class com.xoomcode.acidmaps.adapter.JCAdapter
Could not initialize class com.xoomcode.acidmaps.adapter.JCAdapter/ows:ExceptionText/ows:Exception/ows:ExceptionReport

This is my test script

http://localhost:8081/geoserver/wms?service=AMS&version=1.1.0&request=GetMap&layers=sf:bugsites&styles=&bbox=590223.4382724703,4914107.882513998,608462.4604629107,4920523.89081033&width=938&height=330&srs=EPSG:26713&format=image/png&VALUE_COLUMN=cat&SIMPLIFY_METHOD=3&SIMPLIFY_SIZE=90&INTERVALS[]=10,20,45,70,100&INTERVALS_COLORS[]=0xffffff80,0xff000080,0xffff0080,0x00ff0080,0x0000ff80&RENDERER_TYPE=2&INTERPOLATION_STRATEGY=2&radius=40