"covertPowerVMLunToDecimal" doesn't appear in any of our bug history. I'd recommend getting a support case open. For your support case, you will want to supply the datasource "recording" zip file for the failing datasource
It is worth mentioning that Data Source Service Pack 4 has been released - this is a way of upgrading your OCI 6.3.2's data source code to the latest and greatest, which happens to be the same level as OCI 6.3.3 . I don't believe installing SP4 will actually solve this issue.
Just to close out the loop - engineering came up with a workaround for the old VIOS version on P5 hardware we encountered. This datasource patch is available from NGS, and will ship in a future Data Source service pack for 6.3.x.