We have an application that had been running happily in JBoss 2.4 for quite some time. We've just migrated from DB2/AS400 to MS SQL server/Win2k, and we're also trying to upgrade to JBoss 3.0.6. Yesterday I moved some users onto a new server, and ran into database locking problems.
The application doesn't use any CMP at all - all the DB access is done directly through hand coded SQL (why do you think I want JBoss3!). Anyway, I have noticed that the way transaction isolation levels are handled seem to have changed - looking at the trace monitor for SQL server I see 'set tx isolation ...' commands issued.
The problem we get is process-deadlocks in the _database_ - now I know that I cant really blame JBoss for this, but I'm wondering if there's some config defaults that I haven't changed that I should.
I've attached our mssql.xml for those interested.