I suspect you missed the configuration changes between jboss 3.0 alpha and the cvs version. The cvs version is documented in ch 3 of the manual.
3.0 alpha needs tags like
cvs needs tags like
This seems fixed now - I'm now using 'localhost' rather than my real hostname.
I had another similar problem...
I copied the file classes12.zip into lib/ext &
took the sample OracleDS file (referencing classes12.zip) from the docs - but it could not find the oracle driver.
But if I changed the name to classes12.jar and (subsequently the name of the archive in the oracleDS xml file) then it worked!