Problem solved. Thanks for all the tips, but the bottom line was: I'm an idiot.
The single $ was not the problem either, double $$ inside quotes was originally used, a guy I spoke to suggested I test without, I just happened to copy the script text while I was testing...
After checking more closely, it turns out that the problem was completely unrelated to Kix.
The tested home computers all had too many local drives, thus the U: drive was already taken when I tried to map to it.
I will go and kill myself in shame now.
Anyway, thanks everyone for all the feedback! Cheers, Anders
