Filter equality does not work for tuples

From the documentation I understand that it should be possible to filter a relation based on the equality of tuples. http://wiki.apache.org/pig/PigTypesFunctionalSpec , http://hadoop.apache.org/pig/docs/r0.5.0/piglatin_reference.html#deref:

However with this data file

– indext.txt:
(1,one) (1,ONE)
(2,two) (22, twentytwo)
(3,three) (3,three)

I run this pig script:
A = LOAD 'indext.txt' AS (t1:(a:int, b:chararray), t2:(a:int, b:chararray)); B = FILTER A BY t1==t2; DUMP B;
Expecting the output:
((3,three),(3,three))

However there is an error:
2010-02-03 09:05:20,523 [main] ERROR org.apache.pig.tools.grunt.Grunt

• ERROR 2067: EqualToExpr does not know how to handle type: tuple
  > Pig Stack Trace
  > ---------------
  > ERROR 2067: EqualToExpr does not know how to handle type: tuple
  > org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1066:
  > Unable to
  > open iterator for alias B
  > at org.apache.pig.PigServer.openIterator(PigServer.java:475)
  > at
  > org.apache.pig.tools.grunt.GruntParser.processDump(GruntParser.java:
  > 532)
  > at
  > org
  > .apache
  > .pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.
  > java:190)
  > at
  > org
  > .apache
  > .pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:166
  > )
  > at
  > org
  > .apache
  > .pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:142
  > )
  > at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:89)
  > at org.apache.pig.Main.main(Main.java:397)
  > Caused by: org.apache.pig.impl.logicalLayer.FrontendException: ERROR
  > 1002:
  > Unable to store alias B
  > at org.apache.pig.PigServer.store(PigServer.java:530)
  > at org.apache.pig.PigServer.openIterator(PigServer.java:458)
  > ... 6 more
  > Caused by: org.apache.pig.backend.executionengine.ExecException:
  > ERROR 2067:
  > EqualToExpr does not know how to handle type: tuple
  > at
  > org
  > .apache
  > .pig.backend.hadoop.executionengine.physicalLayer.expressionOperat
  > ors.EqualToExpr.getNext(EqualToExpr.java:108)
  > at
  > org
  > .apache
  > .pig.backend.hadoop.executionengine.physicalLayer.relationalOperat
  > ors.POFilter.getNext(POFilter.java:148)
  > at
  > org
  > .apache
  > .pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
  > .processInput(PhysicalOperator.java:231)
  > at
  > org
  > .apache
  > .pig.backend.local.executionengine.physicalLayer.counters.POCounte
  > r.getNext(POCounter.java:71)
  > at
  > org
  > .apache
  > .pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
  > .processInput(PhysicalOperator.java:231)
  > at
  > org
  > .apache
  > .pig.backend.hadoop.executionengine.physicalLayer.relationalOperat
  > ors.POStore.getNext(POStore.java:117)
  > at
  > org
  > .apache
  > .pig.backend.local.executionengine.LocalPigLauncher.runPipeline(Lo
  > calPigLauncher.java:146)
  > at
  > org
  > .apache
  > .pig.backend.local.executionengine.LocalPigLauncher.launchPig(Loca
  > lPigLauncher.java:109)
  > at
  > org
  > .apache
  > .pig.backend.local.executionengine.LocalExecutionEngine.execute(Lo
  > calExecutionEngine.java:165)

Thanks
Neil