[Chameleon] MapNotes - why delete the shapefile?

[Ken-ichi]

Hi all,

I'm trying to hack the MapNotes widget to operate off of a static  
shapefile instead of a different one for each session, so the notes  
are persistent across sessions.  I've got it accepting a new paramter  
in the template tag, and it tries to edit the shapefile specified  
there, but it borks when properties.php tries to unlink the SHP and  
SHX files in the updateShapeFile() function, because Apache doesn't  
have permission to delete those files.

I suppose I could ask my friendly neighborhood sysadmin to make  
Apache the owner of those files, but why does properties.php delete  
the files anyway?  Is MapScript incapable of doing any kind of  
editing other than appending to a shapefile?

-Ken-ichi