Setting up my new PDM15 on the weekend I ran into a problem where the PDM manager said the firmware was a newer version and I needed newer software.
I was using the latest version on the website.
On the USB stick included with the PDM I found a newer beta version of the PDM manager, but it had the same issue.
Reported firmware version on the PDM was V1.91N
I was able to downgrade the firmware to whatever was included with the PDM manager and it seems to work, but it seems a bit ridiculous to ship something with unusable firmware in it.