Flume to Hbase columns with regexp

Hi,
I am sending a Flume event to insert some information into a concrete HBase table. My flume conf.properties looks like this:
agent.sinks.hbaseSink.table=table_name
agent.sinks.hbaseSink.columnFamily=idColumn
agent.sinks.hbaseSink.serializer=org.apache.flume.sink.hbase.RegexHbaseEventSerializer
agent.sinks.hbaseSink.serializer.regex=^([^,]+),(.+)$
agent.sinks.hbaseSink.serializer.columns = column1,column2

Basically, what I am trying to do is splitting the input values into three different columns: idColumn,column1,column2
With this configuration, no error is returned but no input is recorded into the table. Any idea about what am I doing wrong?

Thanks in advance