asterisk users - May 2005 - Audio delays during file playback and zap channel activity

Hi -

I've noticed that I'm getting audio delays when asterisk is playing  
back a file from disk and new zap channels are being created or  
destroyed.  Audio streams are generally fine (person to person calls  
do not experience this issue).  Sometimes the drops are very short -  
barely noticeable.  Sometimes they are up to 1 second, and whatever  
file is being played resumes at the same spot after the drop is done  
(E.G. On a voicemail call, Allison says "You have five old messages.  
Pr [PAUSE] ess one for....").  The issue exists across all file types  
(gsm, wav, mp3, etc).  It seems to happen on every zap channel  
creation/destruction, but some are so short that it just sounds like  
an audio anomaly rather than a delay.  When there are no active zap  
channels, the issue does not exist.  The disk controller and the Zap  
card do not share an interrupt (The zap card has its own interrupt -  
not shared with anything).

We're running a version of CVS HEAD from 04/09/05 on a Dell PE 1600SC  
with a U320 SCSI, Raid 1 (LSI Logic / Symbios Logic 53c1030 PCI-X  
Fusion-MPT Dual Ultra320 SCSI), with a TE410P connected to a PRI.

Has anybody experienced anything similar?  Anybody have a clue as to  
what's going on?  Zttool does show 15 IRQ misses, but that is over  
the course of  the past week, and after new incidents the number of  
misses stays the same.

Thanks,
Noah