Input plugin JDBC with MSSQL 2000

Hi there,
Im wondering if something achieved to use the jdbc input plugin with MSSQL 2000 (yeah quite old).
I got the sqljdbc.jar from microsoft, but, with the default java installed (jdk 1.7) I've got an error type Java::JavaLang::UnsupportedOperationException: telling me that I should use the sqljdbc4.jar driver.

If i switch to jre 1.5, logstash dont even start

Exception in thread "main" java.lang.UnsupportedClassVersionError: Bad version number in .class file
at java.lang.ClassLoader.findBootstrapClass(Native Method)
at java.lang.ClassLoader.findBootstrapClass0(ClassLoader.java:892)
at java.lang.ClassLoader.loadClass(ClassLoader.java:302)
at java.lang.ClassLoader.loadClass(ClassLoader.java:300)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)

I cant use sqljdbc4, because it doesn t handle MSSQL 2000.

My environment :
Logstash 2.2.2 under ubuntu 14.04

Regards,

Raphael.