the complete code is very long and has a lot of stuff, that has nothing to do with the part, that is causing the problem.
should i post it anyway?
and yeah i know that.
it seems like, when i send stuff with the software serial it screws with the buffer of serial3.(could that be?)
changes some bytes for what ever reason, which causes the if( puffer[4] != (byte) comein_3[9] ) to become true, despite the fact that the some transponder is beeing read.