[BRLTTY] can't start brltty in the live-CD grml

[Hermann]

Hi to all,
I'm new here: My name is Hermann and I live in Germany.
I use several Linux live-CDs such as knoppix, which I think is also 
known outside of Germany.
Since a few months I prefer a distribution named grml, that is developed 
by an Austrian team. It also contains brltty and until the latest 
version of grml (0.7) it worked well.
Since that version I encounter several problems:
It is not possible to run brltty after starting grml. When I enter:
brltty -b bm -t text.de.tbl
which is the string for my braille display, (Vario 40 by Baum) nothing 
happens.
Like many live-CDs, grml shows a boot prompt, before starting the 
system. You can enter here (in my case)
grml brltty=bm,/dev/ttyS0,text.de.tbl
so that the braille display starts with the system; this works.
It is also possible to create a file with several start parameters to 
automatize the process; that also works.
And, to complete the confusion, when I copy a prepared brltty.conf file 
and then invoke brltty with the parameters like said in the first 
example it also works.
What went wrong with brltty? In former versions of grml the team 
compiled the package with brltty 3.4.1, since version 0.7 the use brltty 
version 3.7.2 and the trouble began.
Another problem was that I had to figure out, that the start parameters 
for the Baum display has changed from "va" or "vh" to "bm".
The man-pages contain the old parameters despite the fact, that they 
describe version 3.7.2. However the help screen showed me the right way, 
although I had to guess the name of the parameter; first I thought that 
the right parameter was "ba", which is obviously not true.
The online documentation made everything clear, but the problems with 
the command line still remain.
Any idea what's going on?
Best regards
Hermann