Question : DHCP server returning address from wrong scope.

I am adding a new switch for a new office.  The existing network works like this:

The DHCP server is: 192.168.1.4.  It has three scopes defined.  192.168.1.x, 192.168.3.x and 192.168.4.x.  3.x and 4.x are identically configured.

192.168.1.0/24: the primary network served by a Procurve 3400
192.168.3.0/24: a remote office service by a Procurve 2626 (this network works perfectly)
192.168.4.0/24: remote office served by a Procurve 2610.  Routing is fine.  Only DHCP doesn't work right.  DHCP addresses returned by PCs on this switch are 192.168.1.x (but should be 192.168.4.x).  This switch is configured identically to the 2626.

What am I missing?

Answer : DHCP server returning address from wrong scope.

OK, so it appears there are no additional routers between the switches.
I guess that the link between thw switches is via ports 22 on switch 1, port 26 on siwtch 3 and port 26 on switch 4.
(BTW: Why do you have "vlan 2 tagged 25" in switches 3 and 4? Is there a backup link between them via those ports?)

Anyway, I think you should remove the lines "vlan 1 tagged 22" on Switch 1 and "vlan 1 tagged 26" on Switch 3 and 4.
These statements join the  various vlan 1's into just one big vlan 1.
While the "v" for "virtual" may make this setup practical if you don't want to sesort to routing, it contradicts the "l" for "local".
In fact this setup makes the vlan 1's a single broadcast domain and hence
- broadcast noise (esp. by Windows hosts) fills up the WAN link
- remote hosts can obtain a DHCP lease directly from the DHCP server (and hence from its directly connected address range 192.168.1.0/24).