I'm struggling with the same problem and when I try to test the server connection it gives me the following error message.
WebSphere MQ server MyMQServer connection test failed for WebSphere MQ queue manager QM_bss_spare_03 with an exception: *MQ resource discovery classes are not available.*"

1) What is the value of MQ_INSTALL_ROOT? +C:/Program Files/IBM/WebSphere MQ+

2) Does the MQ_INSTALL_ROOT\Java\lib directory exist, and in particular does the file exist? +YES+

3) Are you getting any other WebSphere MQ related messages or FFDCs in system out prior to the one you list below? +I do not get any message other than the one specified above+

4) What is the full version of your install? +WebSphere and MQ 6.0+

Thanks in advance for any help.