Hi,
I would to share our experience about recent versions of Drools.
We found out that 4.0.6 was out on last wednesday, so we decided to move up from 4.0.3 to 4.0.6. We made a few tests but we counted on the fact that backward compatibility was provided. On friday, I went on Drools website and found out that version 4.0.6 was replaced by 4.0.4 whithout any more explaination, I made a research on this list to find out that you had to make a roll back. At the same time we found out a drools bug on our app :

Caused by: java.lang.NullPointerException
        at org.drools.base.evaluators.ObjectFactory$ObjectEqualsComparator.equals(ObjectFactory.java:561)
        at org.drools.base.evaluators.ObjectFactory$ObjectNotEqualEvaluator.evaluate(ObjectFactory.java:158)
        at org.drools.rule.LiteralRestriction.isAllowed(LiteralRestriction.java:61)
        at org.drools.rule.LiteralConstraint.isAllowed(LiteralConstraint.java:82)
        at org.drools.reteoo.AccumulateNode.assertTuple(AccumulateNode.java:156)
        at org.drools.reteoo.CompositeTupleSinkAdapter.propagateAssertTuple(CompositeTupleSinkAdapter.java:30)
        at org.drools.reteoo.FromNode.assertTuple(FromNode.java:90)
        at org.drools.reteoo.SingleTupleSinkAdapter.propagateAssertTuple(SingleTupleSinkAdapter.java:20)
        at org.drools.reteoo.JoinNode.assertTuple(JoinNode.java:107)
        at org.drools.reteoo.SingleTupleSinkAdapter.propagateAssertTuple(SingleTupleSinkAdapter.java:20)
        at org.drools.reteoo.JoinNode.assertObject(JoinNode.java:151)
        at org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:22)
        at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:140)
        at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:318)
        at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:153)
        at org.drools.reteoo.Rete.assertObject(Rete.java:175)
        at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:192)
        at org.drools.reteoo.ReteooWorkingMemory.doInsert(ReteooWorkingMemory.java:71)
        at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:909)
        at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:881)
        at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:682)

We had to deploy our app on friday, so we decieded to rollback to 4.0.4 to find out that we had the same error. So we decided to rollback to 4.0.3, I went to the download section of your site, and found out that previous versions where just unavailable, which is unacceptable. Obviously, I found it on our SVN, but I wasn't very happy about this.

Here are my conclusions :
- We are not going to change our version of Drools soon
- Please give us access to previous versions

Chris