Stoobie, no such popup in my PENG 2.1.8 - just the Windows save-as.
However, I could have saved myself a lot of thinking by visiting the files area, where I found PCF Switcher, a utility by our own mighty Daniel Tonks:
[Link: files.remotecentral.com]

These 433.92 MHz receivers can play some strange tricks- after programming my amps plus lighting into the Pronto SBC RU990 under code #1 and #2 everything stopped working by and by.
Even using the little remote that came with the Elro's for the lighting made lamps not switching ON or refusing to go OFF....
And the 3 amp sockets that I got working OK stopped doing so: one wouldn't go off and one wouldn't go on...

Really looks like these sockets are somehow self learning, although I really cannot see how.
Anyone got a clever remark on this spooky phenomenon?