IllegalArgumentException thrown on a box running java7 with a sorted query

Today we were running into this nice exception on a box running java7 with a sorted query (by lastModified DESC):

java.lang.IllegalArgumentException: Comparison method violates its general contract!
at java.util.TimSort.mergeHi(TimSort.java:868)
at java.util.TimSort.mergeAt(TimSort.java:485)
at java.util.TimSort.mergeForceCollapse(TimSort.java:426)
at java.util.TimSort.sort(TimSort.java:223)
at java.util.TimSort.sort(TimSort.java:173)
at java.util.Arrays.sort(Arrays.java:659)
at java.util.Collections.sort(Collections.java:217)
at
org.apache.jackrabbit.core.query.lucene.join.QueryEngine.sort(QueryEngine.j
ava:625)
at
org.apache.jackrabbit.core.query.lucene.join.QueryEngine.execute(QueryEngin
e.java:484)
at
org.apache.jackrabbit.core.query.lucene.join.QueryEngine.execute(QueryEngin
e.java:126)
at
org.apache.jackrabbit.core.query.lucene.join.QueryEngine.execute(QueryEngin
e.java:115)
at
org.apache.jackrabbit.core.query.QueryObjectModelImpl$2.perform(QueryObject
ModelImpl.java:129)
at
org.apache.jackrabbit.core.query.QueryObjectModelImpl$2.perform(QueryObject
ModelImpl.java:124)
at
org.apache.jackrabbit.core.session.SessionState.perform(SessionState.java:2
16)
at
org.apache.jackrabbit.core.query.QueryObjectModelImpl.execute(QueryObjectMo
delImpl.java:123)