Problem using WEKA v3.4 with MySQL/MyODBC

Dear Weka List,

I'm really looking forward to using WEKA in my research, but I have a
problem importing instances into WEKA Explorer from MySQL.

I would be very grateful if you could suggest anything I might try; these
are the symptoms...

I have WEKA v 3.4, Sun J2RE v1.4.2 running on an NT 4, SP 6 PC 
client talking to an MySQL database (v3.23.58) on a Linux server, via 
ODBC (MyODBC v 3.51.8).

I configured a User DSN called VOICESforWEKA (MyODBC confirms 
it can connect to the data source), and specified the DSN in the 
DatabaseUtils.props file, which lives in the same directory as weka.jar
(the working directory I hope???) and contains two lines...

jdbcDriver=sun.jdbc.odbc.JdbcOdbcDriver
jdbcURL=jdbc:odbc:VOICESforWEKA

When I click on the Open DB... button in WEKA Explorer, a dialogue 
box labelled weka.experiment.InstanceQuery appears. I type 
jdbc:odbc:VOICESforWEKA as the databaseURL, and Select * from 
Pair as the query (username & password are blank, sparseData is 
FALSE) and press OK.

No Instances are loaded, instead, an error dialogue box appears (red 
circle, white x icon), labelled Load Instances, with the message 
'Couldn't read from database: null'.