DLPAR Error

Hello,
This is the foll error wen i try doin DLPAR from my VIO after adding the virtual adpaters on my clients:
HSCL294C DLPAR ADD Virtual I/O resources failed:
com.ibm.hsc.common.exceptions.PIHscClientException: HSCL294C DLPAR ADD Virtual I/O resources failed: HMCERRV3DLPAR020: AIX DLPAR operation a on slot resource failed without throwing exception. The request number is 1. The success number is 0.
The AIX command is:
drmgr -a -c slot -s Uxxx.570.65xxxx-V1-C80 -d 0
The AIX standard output is:
Unknown error.
The AIX standard error is:
Not enough returned data (1)
The RMC return code is 0. The AIX return code is 1140.

appreciate a response