... due to the fact that the CounterFactory uses for "long" types the GeneratedCounterInteger class.

Patch:

Index: ../ebean/src/com/avaje/ebean/server/deploy/generatedproperty/CounterFactory.java
===================================================================
--- ../ebean/src/com/avaje/ebean/server/deploy/generatedproperty/CounterFactory.java (revision 127)
+++ ../ebean/src/com/avaje/ebean/server/deploy/generatedproperty/CounterFactory.java Sat Feb 14 12:54:09 CET 2009
@@ -38,7 +38,7 @@

final GeneratedCounterInteger integerCounter = new GeneratedCounterInteger();

- final GeneratedCounterInteger longCounter = new GeneratedCounterInteger();
+ final GeneratedCounterLong longCounter = new GeneratedCounterLong();

/**
* Create the GeneratedProperty based on the property type.