HP Procurve - Cant access auxiliary switch over network - MGMT VLAN

Hi All

I have a core switch (5412zl) with vlan 100 MGMT configured.

I also have 3 sets of switches downstairs (several floors down) which are connected via fiber. All three switches have MGMT 100 configured and tagged on the fiber port.

x.x.100.20 (Accessible)

x.x.100.21 (Accessible)

x.x.100.22 (Not accessible)

I also have my core switch's fiber ports tagged with MGMT 100 as well.

Now, I can ping/traceroute 100.22 from the core switch -- I can also ping it from other auxiliary switches that have MGMT vlan 100 configured -- but I cannot hit 100.22 from my PC or any other machine on the network.

Any idea what could cause this?