i am using MPEG Layer-3 Audio Decoder 1.9 (build 311) at the moment but it seems that there are problems with it with some files!
i am now searching for an alternative one; which one can be recommended?

try Lame with razorlame gui.
Lame is decoding very well.

See the option to get more help.
maybe lame.exe --decode or something like this...

thanks for your answer but i originally thought about mp3 playback (sorry if "decode" isnt the right word for that).

i have a problem with one mp3 file.
if i play it in winamp with mad decoder plugin the playback is ok (so i think the file itself is alright), but if i use any other player (like bsplayer) there is a failure so i thought it is "MPEG Layer-3 Audio Decoder 1.9 (build 311)" fault?

any ideas?

So winamp with the default FhG codec does not work properly? What about winamp with the mpg123 codec? Foobar with the same codec? 1by1 with mpg123 or MAD?

no the fhg codec doesnt work properly (i just mentioned the mad-plugin to "prove" that the file itself is alright)!

i have to say that i want to mux the mp3 into an avi, so i need an codec to decode the mp3 stream, which is used by players like bsplayer (i guess such codecs are called directshow codecs (*.ax-files) maybe ).

where can i get the mpeg123 codec (is it also available as "directshow codec")?