Indeed, i did try to install it also from a generic SD card reader that can read all kinds of memory cards. But as already stated this was not an option because i only had a 1GB Compact Flash card.
After that i continued to install it via the USB memory stick image with serial output..
I'm still wondering why the memstick image with serial did not work and the one with VGA did.
I did not try to do the ultimate test to install the memstick image with VGA console directly on the XTM510 simply because this is my production gateway to the internet.
When my testbench of my homelab is up and running again, i can do some more tests and let you know.
Thanks!