please read :
http://cdn.procurve.com/training/Manuals/AP530-Install-Oct08-59925444.pdfFrom this document :
>>> The ProCurve Wireless Access Point 530 WW (J8987A) has no preset country
code and must be configured before you can enable radio communications
for the access point. <<<
also from this document :
>>> Also verify that the
wireless station has been configured with an IP address compatible with
the attached network, either manually or via DHCP. <<<
So the AP acts as a dhcp-client to the fixed network. And I don't think the AP acts as DHCP-server, but it expects one allready present on the "local network".
Depending on the DSL provider, there may not be any dhcp-server in its "modem/router".
a solution can be to add an additional router that connects the DSL on the uplink and the AP at one of the local ports.