missing images

dear developers

whenever an image is stored on the file system but is missing, there  
is the following zope error:

   Error Type: TypeError
   Error Value: coercing to Unicode: need string or buffer, NoneType  
found

in such a case, everything is known about the image (format, size,  
scaling, etc.) only the image itself is missing. i wonder if you  
developers could catch this error and use a dummy image (with a  
warning message in it) from the globals directory as replacement. the  
above error doesn't tell an author exactly what is happening; some  
unicode problems. only managers can have a look at the zope error_log  
and find the real reason.

regards,
marc