Error creating a jdbc data source

Hi I am making a new jasperserver box.

I have downloaded version 4.1.0 of jasperserver putting it on a older machine.  I need this to speak to ms sqlserver, so I downloaded JTDS-1-3-1.jar, now when I try and create the connection i get a massive error the only part I can understand is java.lang unsupported class version error, should I be looking for something specific in the error.  Or is the version of jasperserver and JTDS not compatible, if so can someone recommend a better mix?

thanks

here is the error log thanks