[mma] Wierd audio breakthrough routing to tracks-Live6.01

[jackal]

I'm routing all my drums to a channel '1-Compressor', and inserted a URS 1980 comp on this channel...
Now, in sections of the song where there's no kick happening I hear a buzzing breaking through, although only intermittently. If I solo the track I hear this buzzing constantly, and it's not quiet! It also happens with no plugin on the track.
I can work around this using sends, but it seems a bit less elegant to me.