Occasional jogl crashes when using effects in SoMa on Mac OS X 10.6.3

Displaying BarChart sometimes (4 times in 20 tries) crashes with SoMa b29 on Mac. I am not able to reproduce it reliably, even with the same Chart. Happens with different BarCharts.

Configuration of one of the crashing Charts (resolution was 60, highest was 2491, maxviewer 35):

BarChart {
                width: bind width
                height: bind height
                legendVisible: false;
                categoryGap: 0;
                barGap: 0;
                data: barchartSeries
                categoryAxis : CategoryAxis {
                    label: "seconds"
                    startMargin : 0;
                    endMargin : 0;
                    gapStartAndEnd : false;
                    categories: for(s in [0..highest step resolution]) {
                        "{s as Integer}"
                    }
                    axisStrokeWidth: 2;
                    //tickLabelsVisible: true;
                    tickLabelTickGap: 1;
                    tickMarkLength: 5;
                    tickMarkVisible: true;
                };
                valueAxis: NumberAxis{
                    lowerBound: 0;
                    upperBound : maxviewer;
                    tickUnit: if(maxviewer > 10) maxviewer / 10 as Integer else 1;
                    formatTickLabel: function(f) : String {
                        return "{f.intValue()}";
                    }
                    label: "viewers";
                    visible: true;
                    tickLabelsVisible: true;
                }
            }