install problem - keyboard doesn't work through my USB KVM switch

I have a 4-port USB KVM switch. It's marked MT-ViK1 and apparently is a pretty generic piece of hardware, but it's worked well for me so far. I have 3 computers hooked up to it and have installed Debian 8 on all of them through this switch.

When I use the ROS bootcd to install to a desktop, at the prompt to select English as a language, I can't proceed, unless I hook the keyboard directly into the PC.

This issue was discussed yesterday on IRC, and per the suggestions, I've downloaded the debug bootcd, copied the files to a rw directory, and edited this section of txtsetup.sif to create a debug.log file to send to the developers:

[SetupData]

DefaultPath = \ReactOS

OsLoadOptions = "/NOGUIBOOT /NODEBUG"

;DbgOsLoadOptions = "/NOGUIBOOT /KDSERIAL /DEBUGPORT=COM1 /FIRSTCHANCE"

DbgOsLoadOptions = "/SOS /DEBUGPORT=FILE:\Device\Harddisk0\Partition1\debug.log"

;DbgOsLoadOptions = "/NOGUIBOOT /DEBUGPORT=BOCHS"

I then remastered the bootcd using this command:
genisoimage -b loader/isoboot.bin -no-emul-boot -o aaboot.iso debugiso

I remastered several copies, using different variations of the NT path shown above, and none of them have produced c:\debug.log yet. (I used them on the desktop, and also in a VirtualBox VM).

I've spent a lot of time on this and don't know what to try next. If someone would send me a modified version of txtsetup.pif that will definitely work, I will try again and send the debug log.