I apologize if writing in English is not acceptable, but I only understand German enough to read the posts...
I think there might be some wrong checking in the various conversion functions, such as DEC_TO_BYTE, DEC_TO_DWORD, DEC_TO_INT and so on, at least in the plaintext version of the library (oscat276.txt). The IF clause
"IF X > 47 AND x < 56 THEN"
appears in them, but if you check the ASCII table you'll see that it should probably read
"IF X > 47 AND x < 58 THEN"
otherwise characters '9' and '8' will not be evaluated.