jasper crashes on .icns file

Symptoms:
Applications using jasper crashes while trying to read .icns file

How I found it:
On Jaunty, I tried to create a custom application launcher for Zimbra Desktop (with gnome-dektop-item-edit or its panel applet counterpart). When I wanted to assign an icon to this launcher, I tried to open ~/zimbra/zdesktop/zdesktop.webapp/icons/default in the icon browser window, but it made the application crash, everytime.

Launching gnome-desktop-item-edit from the command line, here is the error message I get
"""
jpc_dec.c :1072 : jpc_dec_tiledecode: Assertion `dec->numcomps == 3' failed.
Aborted
"""

The folder had some .png files, one .ico file and one .icns file. If I move the .icns file to another folder, gnome-desktop-item-edit no longer crashes. It seems to come from jasper's bussy handling of ICNS files.
It seems to come from a problem in ICNS handling