Hello everyone, I am getting the following error message when I run my servlet that connects to Oracle (220.127.116.11) and tries to QUERY some data: java.sql.SQLException: ORA-00600: internal error code, arguments: [ttcgcshnd-1], , , , , , ,  I am using JBoss (3.0.6). I have narrowed down the problem and have got to the point where the problem is happening (detail below) - but I have almost no clues what is causing it. What I have found so far is that if the query returns only ONE column (single or multiple rows), it works OK. But if the query returns more than one column (single or multiple rows), I get the error. Seems like some problem with "Oracle JDBC Thin driver". Here is my CLASSPATH: C:\ora92\jdbc\lib\ojdbc14.jar; C:\ora92\jdbc\lib\classes12.jar; C:\ora92\sqlj\lib\runtime12.jar; C:\ora92\sqlj\lib\translator.jar; C:\java\j2sdk1.4.2_01\bin\servlet.jar; I added the first entry (ojdbc14.jar) as per suggestion from someone on another forum but nothing has helped so far. Is there someone out there who may shed some lihgt on this and help fix the problem, please? TIA Just for information: I had Oracle8i on my PC but due to some problems with my Windows, I reinstalled the Windows/2000 (Clean install) and this time installed Oracle 9i (18.104.22.168). No there are traces of Oracle 8i stuff on my PC (as far I know - bcoz I cleaned it). I am not sure if and how JBoss is able to use Oracle8i JDBC driver (if this is the case at all).