Day 7: at least some of the frustrations are over, for now
If I wait a few minutes after switching on the radio I don’t have any TX-problems.
I got a reply from ML&S that I can return the bad adaptor plugs but they don’t have any better ones. I still have to check if it’s even worth sending them back, shipping costs will probably be higher than their value.
The CAT works! I uninstalled com0com and started from scratch. I’m using W7pro on my PC and the procedure to get com0com from this site and then followed the tips from the DXLabsuite site again and now it works like a charm! TIP: the readme-file that is included with com0com at this time is not correct. The procedure to get everything up and running is the one from the DXLab site (at least for 64-bit W7):
disable User Account Control (UAC) on your pc and reboot
install com0com
create a COM-pair
use one of the created COM-ports for the transceiver and the other one for the logging program