Unable to find problem wsp file which is filling my disk with log messges

My console.log file is filing up with a great deal of stack traces like the one below. I'd guess from reading Bug #758261 that one of my .wsp files is corrupt. I have no zero length wsp files, and (brute force alert) running whisper-info or whisper-fetch on all of my wsp files resulted in no abnormal output.

I've tried using strace to figure out what file is being access by this message but it's not useful. When my log filesystem fills up graphite stops answering the sockets and recording data.

How do I track down what is causing me this problem?

Thanks

01/12/2011 21:24:33 :: Unhandled Error
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/twisted/python/threadpool.py", line 210, in _worker
    result = context.call(ctx, function, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/twisted/python/context.py", line 59, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/usr/lib/python2.6/dist-packages/twisted/python/context.py", line 37, in callWithContext
    return func(*args,**kw)
  File "/opt/graphite/lib/carbon/writer.py", line 157, in writeForever
    writeCachedDataPoints()
--- <exception caught here> ---
  File "/opt/graphite/lib/carbon/writer.py", line 124, in writeCachedDataPoints
    whisper.update_many(dbFilePath, datapoints)
  File "/usr/local/lib/python2.6/dist-packages/whisper.py", line 515, in update_many
    return file_update_many(fh, points)
  File "/usr/local/lib/python2.6/dist-packages/whisper.py", line 549, in file_update_many
    __archive_update_many(fh,header,currentArchive,currentPoints)
  File "/usr/local/lib/python2.6/dist-packages/whisper.py", line 616, in __archive_update_many
    if __propagate(fh, header, interval, higher, lower):
  File "/usr/local/lib/python2.6/dist-packages/whisper.py", line 421, in __propagate
    (lowerBaseInterval,lowerBaseValue) = struct.unpack(pointFormat,packedPoint)
struct.error: unpack requires a string argument of length 12