If you have Rational Business Developer SOA and Rational Developer for System i and HATS installed, it will not update. There is a known issue, which we have been waiting to be fixed and although there are now new updates it is still there. This technote provides the details on how to get around this.

Update 3rd August: This details an iFix on how to get around the issue.
http://www-949.ibm.com/software/rational/cafe/thread/1098?tstart=0