Sound stops when I mount NTFS partition.

FreeBSD 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #0: Mon Nov 10 06:28:52 VLAT 2008  i386

When I'm trying to mount ntfs partition, my music (musicpd or mplayer) is stopping for a few seconds with "jzzz" sound).
I encountered a similar problem some time ago, but with mount_smbfs. The Problem is, this comes only for the first time, when the kernel module must be loaded. My solution - or no, better 'work around' - was to load the kernel at boot time. Then this problem vanished. I don't analyse this issue further, because the workaround works for me. Maybe some other could enlighten us about the real cause?
I think when a module is loaded the kernel rescans all unclaimed devices and probably locks something in the process (some ithread/Giant). Which causes the sound driver to stop responding (waiting for that lock) and probably the current sound buffer to start repeating itself until the lock is released (or some situation close to that) :).