We are using Drools engine on our client written in C#. We are using IKVM to convert the drools jar and our java beans into dll's using IKVM. We have a rule similar to this:-

rule "aggregate rule"
when
$b : Bill(billAmount > 100)
$n : Number(doubleValue > 100) from accumulate ( $l : LineItem() from $b.findItems("color", "blue"), sum($l.getSellingValue()))
then
VoucherSeries fact0 = new VoucherSeries();
fact0.setSeriesCode( "aggregate voucher" );
insert(fact0 );
voucherlist.add(fact0);
System.out.println("sum" + $n);
end

This rule works fine when it is run with java based drools API's, but while running it with IKVM converted drools, it throws the following error:-

Unable to cast object of type 'AccumulateMemory' to type 'FromMemory'.

Any ideas on what might be going wrong ?

thanks,
piyush