Routing problem from virtual to physical

Hi all,

I have a strange problem and it is driving me crazy! Routing seems not
to work correctly.

So what did I set up?

I have a NAS device on 192.168.101.3/24 with default GW 192.168.101.1 on
VLAN101 on a managed CISCO switch
The GW IP 192.168.101.1/24 is the IP of one OPT interface of the FW
which is in VLAN101 too.

I can ping the NAS device from the firewall when I use the GW interface.
But from any other interface I can not ping it.
There is no NAT active and "Enable advanced outbound NAT" is checked to
disable NATing.

Other virtual hosts within the same subnet (VLAN101) can be accessed
from any other subnet. Just the physical NAS host is only reachable from
the FW itself. (and only when you ping it from the Interface of the FW)

It seems as if routing to physical is a problem.

Any idea?