Windows PVR-builds: radio-playback problem

Hello Forum,

I stumbled upon a problem when playing radio (DVB-C) with the latest pvr-builds from dushmaniac and margro.
I configured XBMC to use milkdrop as a visualization when radio is playing, and it does so.
The problem is that milkdrop displays something like zero.point.5 frames per second, whereas while playing music it performs absolutely fluently. Also, when radio is playing with that stuttering milkdrop dripping some graphics, XBMC becomes nearly unresponsive. E.g. pressing the stop-button on my remote takes about 5 seconds before making XBMC stop the radiostream.
Is this a known issue?
I made a debug-log, but I couldn't find anything suspicious.
The DVB-C-radio is mp2-encoded, which shouldn't be a problem.
Haven't tested another visualization though, so it might be a problem within milkdrop, but it's difficult for me to imagine that.
Any ideas?

I have also DVB-C radion but unfortunately I can't reproduce this...