Restart fails and Intel X550-T2 not found

[L4R5]

Hi,
we have a Boston Server with an Inel X550-T2 expansion card. The system doesn't power cycle right. It fails to boot the system. Only after power reset and cold start we managed to boot the system but the expansion card doesnt get recognised. The onboard NICs get recognised but failed to establish the connection.

We have the same system with an other expansion card. This system behaves as it should.
Anybody similar problems?