"On BC1-2004 I select source with the beo4 on Bc1 -2001 all could be accessed by beo1."
What happens with BC1-2004 when you press MENU on Beo4?
"So there must be a software or hardware difference between Bc1-2001 and BC1-2004 ?"
Maybe. Sorry, I can`t help with BC1, because I don`t own one. I just got a Beo1.
"btw as I reprogrammed the beo1 towards beo4 commands. Will it still be possible to use it on the BC1 -2001 as it did before reprogramming ?"
I don`t think so. But try and let us know....
"And if not how is it reversable ?"
Usually it`s the same sequence once more (think of Beo4 reprogramming for LINK codes), but I can`t test it, because I don`t have a BC1 as said before.
Stefan