DL585 G7 Power supply issues

[PS-Support T-Systems]

Hello at all,

HP is not able to help us and cannot reproduce the following issue right now.

We have our test machine configured with 2+2 powersupplies (2_required 4_redundancy) as shown in RBSU Guide for DL580 G7 (it works on 585 G7 too altough it's not documented).
But we observed a strange behavior: the machine is going to reboot (or shutdown) if the 2 required powersupplys are connected well.
This issue is reproducable app.4 times if we test the machine in failover tests.
Has anyone seen this already?
RBSU settings are ok, a configfile got by conrep shows us the correct setting.
SystemROM version is the latest (01/29/2011) and iLO3 FW (1.20) too.