PCM v2.3 and modern 3500/5412 firmwares config issue

[WrightHassall]

I have an old implementation of ProCurve Manager Plus v2.3 (v2.32 build, I believe) on a Server 2008 R2 server, which works nicely but since upgrading the firmware on one or two of the switches to a newer version I am no longer able to interrogate the switch using PCM to download the software configuration. I am using SCP to access the configuration (completely disabled the TFTP daemon as it's not secure enough). SCP works fine for switches running the older of the two following versions of firmware, but not for the later version:

Switch firmware Current Version

ROM: K.12.12

SW Version: K.13.45

Scanning for configuration works fine.

Switch firmware Latest Version I will be rolling out ASAP

ROM: K.15.28

SW Version: K.15.07.0008

Scanning for configuration starts but never finishes.

As far as the Manager is concerned, everything else seems to work fine. SNMP monitoring of health and re-discovering the devices works as expected but i can just never get the configs into PCM so i can use change-control.

Any ideas? I've attached a screenshot of the outcome after the Config Scan has been completed. The 'Result' column just shows a symbol but does not download the config.