Howdy, When using the MonetDB JDBC driver on JDK6 (or JRE6) > 6.10 you will get IndexOutOfBoundsExceptions when using transactions (possibly in other cases as well). This happens because there is a bug in CharBuffer.subSequence(), which is used in StartOfHeaderParser.java The following patch remedies this problem, without any regressions as far as I can tell. Recompiling the JDBC driver is all that's required. You'll still have to compile with the 1.5 option because the JDBC interface changed quite a bit between 5 and 6, but if I have time left I might fix that as well. Hope this'll help someone. --- MonetDB-java/java/src/nl/cwi/monetdb/mcl/parser/StartOfHeaderParser.java Wed Mar 04 12:21:50 2009 +++ MonetDB-java/java/src/nl/cwi/monetdb/mcl/parser/StartOfHeaderParser.java Thu May 07 11:57:47 2009 @@ -141,8 +141,7 @@ while (soh.hasRemaining() && soh.get() != ' ') { cnt++; } - soh.reset(); - return(soh.subSequence(0, cnt).toString()); + return(soh.slice().subSequence(0, cnt).toString()); } }