No images after upgrade to 1.1

[rxm8028]

I have been succesfully running zabbix-1.1beta12, and have spent much time creating a 'visual' representation of my network using the 'maps' feature. I upgraded to 1.1 this moring, and zabbix runs, but images no long appear. If I look in the 'Configuration, General, Images' area, I see the list of images, but all say 'No image' in the right column. Adding or deleting images has no effect.
If I click the 'no image' link, I get a message that reads '
Fatal error: Call to undefined function: set_image_header() in /srv/www/htdocs/image.php on line 39'.

I looked in the database using MySQL Control Center, and it appears that all of my images are still in the images table as blobs.

Any idea what might be wrong?

[rxm8028]

Oops. I found it

Apparently one or more of the php frontend files did NOT copy correctly when I copied from my installation source to the web serveer directory.