Errors/Warnings during system scan
CONFLICTING_VIBS ERROR […] Remove the conflicting vibs or use Image Builder to create a custom ISO providing newer versions of the conflicting vibs
[Broadcomm_bootbank_net-bnx2_2.2.5dv55-10OEM.550.0.0.1331828]
Are you all using the HP 5.5 U1 ISO released in March 2014? Or the just recently released updated June 2014 HP 5.5 U1 ISO?
http://h18004.www1.hp.com/products/servers/software/vmware-esxi/driver_version.html
The March ISO contains the driver net-bnx2 - Version - 2.2.4f.v55.3, which is older than the reported driver in the message above. This might be the reason it refuses to update.
So make sure you're using the recent June HP ISO:
https://my.vmware.com/web/vmware/details?downloadGroup=HP-ESXI-5.5.0U1-GA&productId=353
Name: VMware-ESXi-5.5.0-Update1-1746018-HP-5.74.27-Jun2014.iso
Release Date: 2014-06-17
Build Number: 1746018-5.74.27