Tasks with null arguments fail to execute on the Bamboo Agents

INFO   | jvm 1    | 2011/10/24 11:33:00 | 2011-10-24 11:33:00,261 INFO [1-BAM::192.168.15.69::Agent:pool-3-thread-1] [Command] Decorated command line is: [clover.fullclean, -Djava.io.tmpdir=/var/folders/lP/lP62EjPBHByizrradFuOxk+++TM/-Tmp-/TEST-ATEST-JOB1, -f, build.xml, clean, -Dclover.skip.json=true, -Dclover.skip.report=true, -Dclover.optimization.enabled=false, -lib, null, -listener, com.atlassian.clover.ci.AntIntegrationListener, -Dclover.license.path=/Users/asridhar/bamboo-agent-home/xml-data/build-dir/TEST-ATEST-JOB1/.clover/clover.license]
INFO   | jvm 1    | 2011/10/24 11:33:00 | 2011-10-24 11:33:00,302 FATAL [1-BAM::192.168.15.69::Agent:pool-3-thread-1] [ExecuteBuildTask] Failed to execute the build 'TEST-ATEST-JOB1-4'
INFO   | jvm 1    | 2011/10/24 11:33:00 | java.lang.NullPointerException
INFO   | jvm 1    | 2011/10/24 11:33:00 |       at org.apache.tools.ant.types.Commandline.quoteArgument(Commandline.java:346)
INFO   | jvm 1    | 2011/10/24 11:33:00 |       at org.apache.tools.ant.types.Commandline.toString(Commandline.java:381)