I didn\'t know where to write something about this and decided to do it here.
After loooong time debugging my program I could find out that calling Driver.getConnect
I had the exact same issue where jBoss would hang on driver.getConnection(). However, I was using jBoss EAP 5.1, java 1.6.0_37x64, Sql Server 2005, and jtds1.2.5 as my jdbc driver.
The work around I had to use was a jvm setting at startup: -Djsse.enableCBCProtection=false and that resolved it.
I don't consider this a fix, but rather a work-around at this point.
I did find a bug: 7105007 : Microsoft & jTDS JDBC driver broken after update to 1.6.0_29 that was very similar, but had a different cause. What was interesting was that it showed up on both the MS drivers and jtds drivers.