C3P0 Statement.close deadlock - jdbc

Question

Google returns lots of people with deadlock issues in C3P0, but none of the solutions appear to apply (most people suggest setting maxStatements = 0 and maxStatementsPerConnection = 0, both of which we have).
I am using a ComboPooledDataSource from C3P0, initialised as;
cpds = new ComboPooledDataSource();
cpds.setDriverClass("org.postgresql.Driver");
cpds.setJdbcUrl("jdbc:postgresql://" + host + ":5432/" + database);
cpds.setUser(user);
cpds.setPassword(pass);
My query function looks like;
public static List<Map<String, Object>> query(String q) {
Connection c = null;
Statement s = null;
ResultSet r = null;
try {
c = cpds.getConnection();
s = c.createStatement();
s.executeQuery(q);
r = s.getResultSet();
/* parse result set into results List<Map> */
return results;
}
catch(Exception e) { MyUtils.logException(e); }
finally {
closeQuietly(r);
closeQuietly(s);
closeQuietly(c);
}
return null;
}
No queries are returning, despite the query() method reaching the return results; line. The issue is that the finally block is hanging. I have determined that the closeQuietly(s); is the line that is hanging indefinitely.
The closeQuietly() method in question is as you would expect;
public static void closeQuietly(Statement s) {
try { if(s != null) s.close(); }
catch(Exception e) { MyUtils.logException(e); }
}
Why would this method hang on s.close()? I guess it is something to do with the way I am using C3P0.
My complete C3P0 configuration (almost entirely defaults) can be viewed here -> http://pastebin.com/K8XDdiBg
MyUtils.logException(); looks something like;
public static void logException(Exception e) {
StackTraceElement ste[] = e.getStackTrace();
String message = " !ERROR!: ";
for(int i = 0; i < ste.length; i++) {
if(ste[i].getClassName().contains("packagename")) {
message += String.format("%s at %s:%d", e.toString(), ste[i].getFileName(), ste[i].getLineNumber());
break;
}
}
System.err.println(message);
}
Everything runs smoothly if I remove the closeQuietly(s); line. Both closing the ResultSet and Connection object work without problem - apart from Connection starvation of course.