HP 5412ZL switch - web management interface has stopped working and will not enable

[dl_wraith]

I've recently encountered a very irritating issue that I can't seem to get around. I'm hoping someone out there has seen this before.

I have an E5412zl switch chassis populated with J9550A and J8702A modules running firmware K.15.06.0008. The switchg seems to have been set up with default settings so recently I started to edit a few basic settings. After I'd completed the edits I found I could no longer reach the web management interface and nothing I do seems to bring it back.

The settings I changed were all via a telnet session and were:

Set Manager password

Set Operator password

Set SNMP community strings

Set web-management interface to SSL

Use 'Crypto host-cert' command to generate a self-signed cert for the SSL connection

Add Inteface names to 20 + interfaces

Saved config using 'Write memory'

Annoyingly, after all these settings were applied the web interface was still responding and using the cert as intended but once you got past the usual 'cert could be untrusted!' warning it would deliver me to a HTTP 400 error. All I can get now is a http 400 error when trying to get to the web interface on any of the IPs associated with the switch chassis from any connected VLANs. 

Since then I've cleared the passwords, reset the community strings, set the web management interface back to plaintext, zeroized the crypto setup and restarted the switch chassis. I even played around with the IP authorized-managers options to ensure my workstations had the rights to connect and checked which VLAN was set as the management VLAN.

At no point have I lost the ability to manage this via telnet and nothing I do makes the web-management config line appear in the running config (viewed via 'write terminal').

I clearly have screwed something up here and the only similar thread I can find is here: http://h30499.www3.hp.com/t5/ProCurve-ProVision-Based/HP-ProCurve-5400-web-console-issue/m-p/2328449/highlight/true#M88 but sadly there's no clear conclusions or solutions there. My personmal thought is that it was either setting the passwords or changing the web interface mode that's done this but I'd have expected the feature to return once I'd reset the changes.

Anyone else seen this or have any advice on how I can get my web-interface back?

Sorry to ask but this is driving me batty!