[Chameleon] raster hang

[Ken-ichi]

Hi folks.  I've started trying to add a GeoTIFF to my Chameleon app, and 
it really bogs it down, sometimes to a stand still.  The image I'm 
experimenting with is a 29mb unsigned 8bit GeoTIFF created in Erdas.  
The hangs are most frequent when the tiff occupies the whole map, and 
when I say hang, I mean that the map just doesn't render.  The hangs 
also seem to generate an httpd process that takes up a lot (>20%) of my 
CPU activity.  The relevant portion of my map file is pretty simple:

LAYER
    NAME "Test Raster"
    TYPE RASTER
    DATA "/path/to/data.tif"
    STATUS DEFAULT
END

I haven't specified an outputformat, except in the MAP section, where 
I've set it to PNG (but I've switched around and that doesn't seem to 
make much difference).  This problem does not seem to occur outside of 
Chameleon (everything works fine in MapLab's ROSA applet), and it 
doesn't happen every time the map is loaded  (although it inevitably 
happens if you refresh the map enough).

Has anyone experienced this kind of behavior before?  Even better, 
anyone have any recommendations?

-Ken-ichi