Hi, I have uploaded a head.zip file to /clebert-testcase in ftp.jboss.com. All you need to do to replicate this issue is: 1) Unzip head.zip somewhere 2) Download a 4.0.5.GA distribution and open server/default/deploy/hsqldb-ds.xml. Add <use-java-context>false</use-java-context> element inside <local-tx-datasource> element so that the datasource is accessible remotely. 3) Startup the default configuration 4) With IntelliJ, open JBossCache.ipr and run JDBCCacheLoaderTest. You should see most of the tests failing with the stacktrace attached here. This tests are testing that JBossCache can write and read correctly to a backend JDBC cache store. Writing to the db via a remote connection to the datasource seems to work relatively ok, but the stacktrace is produced at reading time, when we get the InputStream and we ask JBossSerialization to create an ObjectInputStream out of it. This does not happen when the DataSource is retrieved locally. I'm a bit busy currently developing a new feature for JBossCache but I should be able to help you at the end of next week to narrow this down. As I said, if you run JDBCCacheLoaderTest with -Dserialization.jboss=false, almost all tests pass and the ones that don't are not because of an issue with serialization itself. I don't have time right now to dig deeper, but I'll have a go in a couple of weeks. Just wanted to send the email so that you have something if you wanna try it yourself. Apologies for not being able to give you more insight to he cause of the issue. Cheers, Galder Zamarreño Sr. Software Maintenance Engineer JBoss, a division of Red Hat IT executives: Red Hat still #1 for value http://www.redhat.com/promo/vendor/